NFR Regional Travel Model – User's Guide - NFRMPO

www.camsys.com

NORTH FRONT RANGE REGIONAL

TRAVEL MODEL

prepared for

North Front Range MPO

prepared by

Cambridge Systematics, Inc.

April 16, 2015

User’s Guide

North Front Range Regional Travel Model

NFR Regional Travel Model – User’s Guide i

Table of Contents

1.0 Introduction ......................................................................................................... 1-1

1.1 System Requirements............................................................................................... 1-1

2.0 Installing the Model Add-In ................................................................................... 2-2

2.1 Folder Structure ........................................................................................................ 2-3

3.0 Running the Model ............................................................................................... 3-1

3.1 Collecting the Required Data .................................................................................... 3-1

3.2 Creating and Running a Scenario .............................................................................. 3-2

Running Selected Model Steps ................................................................................. 3-6

Running Speed Feedback ......................................................................................... 3-7

4.0 Model Utilities - Input ........................................................................................... 4-1

4.1 Edit Network Year .................................................................................................... 4-1

4.2 Create Select Query .................................................................................................. 4-2

4.3 Copy Feedback Results ............................................................................................. 4-2

4.4 Update Input Network .............................................................................................. 4-3

4.5 Edit Network ............................................................................................................ 4-3

5.0 Model Utilities – Transit ........................................................................................ 5-3

5.1 Link/Verify Route System ......................................................................................... 5-3

5.2 Edit Routes ............................................................................................................... 5-3

5.3 Calibrate Constants .................................................................................................. 5-3

6.0 Model Utilities – Maps and Reports ........................................................................ 6-1

6.1 Create Performance Report ...................................................................................... 6-1

6.2 Create Maps (Dashboard) ......................................................................................... 6-1

6.3 Process Turns ........................................................................................................... 6-2

The Built-In Turn Movement Utilities ........................................................................ 6-2

Turn Movement Add-In ............................................................................................ 6-3

Intersection Definition File ........................................................................................ 6-3

Unadjusted Turns ..................................................................................................... 6-5

Adjusted Turns ......................................................................................................... 6-5

7.0 Model Database ................................................................................................... 7-7

7.1 Database Approach .................................................................................................. 7-7

7.2 Database Interface ................................................................................................... 7-8

7.3 Database Tables ..................................................................................................... 7-10

8.0 Transportation Networks ...................................................................................... 8-1


ii NFR Regional Travel Model – User’s Guide

8.1 Transportation Network Components ...................................................................... 8-1

8.2 Example Transportation Network Application .......................................................... 8-2

Before we Begin: Make a Backup Copy ..................................................................... 8-2

Part 1: Prepare Workspace ........................................................................................ 8-2

Part 2: Add New Roadway Link ................................................................................. 8-3

Part 3: Edit the Roadway Segment ........................................................................... 8-7

Part 4: Create a New Model Scenario ...................................................................... 8-10

Part 5: Realign a Transit Route ................................................................................ 8-11

Part 6: Run the Model ............................................................................................. 8-15

9.0 Working with Transit Data .................................................................................... 9-1

9.1 Updating the Route System after Roadway Layer Changes ...................................... 9-1

Maintaining Route System Integrity ......................................................................... 9-1

9.2 Route System Link and Verify ................................................................................... 9-2

9.3 Editing the Route System ......................................................................................... 9-2

Route Direction ........................................................................................................ 9-3

Stop Placement ........................................................................................................ 9-3


NFR Regional Travel Model – User’s Guide iii

List of Tables

Table 1: System Requirements ................................................................................................... 1-1 Table 3.1: NFR Model Folder Structure ....................................................................................... 3-1 Table 6.1: Map Types ................................................................................................................. 6-1 Table 6.2: Map Options .............................................................................................................. 6-2 Table 7.1: Access Database Tables ........................................................................................... 7-10


NFR Regional Travel Model – User’s Guide v

List of Figures

Figure 2.1: NFR Model Add-Ins Settings ..................................................................................... 2-2 Figure 2.2: NFR Model Folder Structure ..................................................................................... 2-3 Figure 3.1: The Scenario Toolbox ............................................................................................... 3-3 Figure 3.2: The Scenario Editor (Input Tab) ................................................................................ 3-4 Figure 3.3: The Scenario Editor (General Tab) ............................................................................ 3-4 Figure 3.4: The Scenario Editor (Output Tab) ............................................................................. 3-5 Figure 3.5: The Scenario Editor (Advanced Tab) ......................................................................... 3-5 Figure 3.6: The Model Dialog Box ............................................................................................... 3-6 Figure 3.7: Sub-Steps Dialog Box ............................................................................................... 3-6 Figure 4.1: Add/Delete Network Year Dialog Box ....................................................................... 4-1 Figure 6.1: The Process Turns Dialog Box ................................................................................... 6-3 Figure 6.2: Editing the Intersection Definition File ..................................................................... 6-4 Figure 7.1: Access Database Form Interface ............................................................................... 7-9 Figure 7.2: Data Scenario Management ................................................................................... 7-10

Introduction

NFR Regional Travel Model – User’s Guide 1-1

1.0 INTRODUCTION

This User’s Guide provides instructions on operation of the North Front Range Regional Travel

Model (NFR Model). Information is provided regarding installing the model, managing model

scenario data, and running the model.

The model is run from the TransCAD software platform through a customized user interface. This

interface provides access to custom calculations developed specifically for the NFR MPO.

Scenario and file management is achieved through a scenario management system integrated

into the custom user interface. A basic understanding of the TransCAD software program is

required to maximize model performance. However, users unfamiliar with the software should

be able to perform some modeling tasks with the assistance of this guide.

1.1 System Requirements

The model must be run on a computer running Windows 7 or later and the TransCAD software

program. Specific system requirements are shown in Table 1.

The listed requirements are suggested minimums; a computer that does not meet these

requirements may still succeed in running the model. Increased processor speeds, multiple

processor cores, and additional memory will reduce the amount of time required to run the

model. The disk space required for installation must be available on the drive where TransCAD

has been installed. The disk space required for additional scenarios can be located on a local or

network drive and must be available before attempting to run the model. However, model run

times will be longer if the model is run from a network drive rather than a local drive.

Table 1: System Requirements

Operating System Windows 7 or later

Processor Intel Core 2 processor or later

Note: Multiple cores will significantly improve model run times.

Memory 4GB – 12 GB

TransCAD Software Version 6.0 r2

Build 9080 or later is recommended.

Microsoft Office (including Access) Version 2007 or later

Disk Space (Installation and Input) 700-800 MB

Disk Space (Each scenario) 8 GB for each scenario, (About 2 GB if some intermediate files are deleted)

Software Type MS Office and TransCAD must either both be 32-bit or both be 64-bit.

Installing the Model Add-In

2-2 NFR Regional Travel Model – User’s Guide

2.0 INSTALLING THE MODEL ADD-IN

Installation of the NFR Model has been streamlined so that the model can be installed in a simple

three-step process. The entire NFR Model is typically provided in a 7-zip file named

NFRMPO_Model_vxxx_mm-dd-yyyy.7z, where xxx is a version reference and mm-dd-yyyy

represents the month, date, and year the installation package was created or delivered.

Installation of the model can be completed by following the three steps described below.

1. Extract the provided 7-zip file and place the resulting folder in a user specified location (e.g., C:\NFR Model v4). The 7-zip file can be extracted using the 7-zip software available from www.7-zip.org.

2. Open the TransCAD software and select Tools Setup Add-Ins… from the main menu. In the dialog box that appears:

a. Click Add to create a new entry b. Modify the new entry as shown in Figure 2.1.

3. Verify the NFR Model dialog box can be started by selecting Tools Add-Ins NFR Model from the TransCAD menu.

If the model dialog box appears, the model installation has been successful. If necessary, pre-

populated scenarios can be modified to reference the installed data.

Figure 2.1: NFR Model Add-Ins Settings

Note: This example assumes the model has been extracted into C:\NFR Model v4. The actual location of the UI

Database entry must be modified if the model is extracted to another location.

http://www.7-zip.org/

Installing the Model Add-In


2.1 Folder Structure

The NFR Model has been set up to use a streamlined file and folder structure that maintains all

model data and macro files within a common folder. This folder can be placed at a user-specified

location anywhere on the computer that will be used to run the model. It is advised the model run

folder is placed on a local drive rather than a shared network drive. The general NFR Model folder

structure is shown in Figure 2.2.

Figure 2.2: NFR Model Folder Structure

Running the Model


3.0 RUNNING THE MODEL

The model is controlled through a series of dialog boxes that allow the user to specify custom

model run settings or to copy settings from a previously defined scenario. Users may also run the

travel model, create reports and maps, and specify model run options. Steps required to

complete a successful model run are described in the following sections.

3.1 Collecting the Required Data

To successfully run the model, various data files are required. Some input files are optional and

will provide additional functionality. Each file is identified by a short keyword as shown in Table

3.1. All input files should be collected and placed in a model input directory. Input files will not be

modified when the model is run. Input files are placed in C:\NFR Model v4\Input when the model is

installed using the example directory location.

Table 3.1: NFR Model Folder Structure

ID Description and Notes Required / Optional

Network The Roadway Geographic File. Required

TurnPen A turn penalty file can be identified to enable specific turn penalties. By default, this file is not present and turn prohibitions or penalties will be applied. If used, this file must be formatted as described in the TransCAD online help system.

Optional

Database The Model Database contains various information items and is further described later in this document.

Required

Routes A TransCAD Route System based on the roadway network geographic file. Required

MODE The TransCAD Mode table compatible with the route system. Required

MODEXFER The TransCAD Mode Transfer table compatible with the route system. Required

TAZ The TAZ geographic file. Required

ParcelData The socioeconomic data parcel data centroid layer.

SelQry The Select link/node query file. If this file is present, select link analysis will be performed when traffic assignment is run.

Optional

KFAC The K-factor matrix file. By default, this file is not present and K-factors are not applied. If used, the K-factor matrix file must be compatible with trip tables output by the model.

Optional

Path** The OUE path files used for traffic assignment warm start. (These files are no loner used and may be removed from future versions of the model)

Optional

Running the Model


3.2 Creating and Running a Scenario

After the input data has been collected, a scenario must be defined from the model dialog box.

Model scenarios are accessible from the scenario toolbox and contain information about the

following:

Input and output directories;

Filenames;

Network year/alternative;

Data year/alternative;

Individual alternatives; and

Advanced settings and parameters.

Scenarios can be copied based on existing scenarios or can be created using default settings.

Figure 3.1 through Figure 3.5 show the scenario toolbox and editor used to manage scenarios

along with annotations describing the available functions.

A scenario can be created or edited using the following steps listed below. It is recommended

these steps are performed in order.

1. Specify a scenario name and identify the scenario input and output directories.

2. As necessary, identify input files by name. Most files will be found automatically, but some files may need to be located manually.

3. Once the status for all required files is shown as “Exists,” edit the scenario settings on the General tab. Note network and data year settings do not need to match. It is possible to run a scenario based on the 2008 roadway network and 2035 socioeconomic data.

4. Optional: Review the output filenames and modify if desired (changes are not typically needed).

5. Optional: Review the advanced settings and modify if desired (changes are not typically needed).

WARNING: The Advanced tab in the Scenario Editor allows the user to edit values that are not often changed. The advanced interface does not prevent the user from entering invalid or inconsistent data, which may cause the model to crash or produce invalid results.

Running the Model


The model dialog box, shown in Figure 3.6, provides flexibility in how the model is run. In most

cases a simple approach can be taken.

To run a standard, complete model run, start the model dialog box, create a scenario, review

file settings, and click on Step 1 – Prepare Networks. The model will be run with the standard

default settings.

To automatically create a performance report when the model run is complete, select the

appropriate checkbox.

If buttons are grayed out and cannot be used, input files may be missing or settings may be

invalid.

Figure 3.1: The Scenario Toolbox

Scenario Status: Ready to run Run Complete Partially Complete Missing Inputs

All scenarios in the scenario file are listed here. Double click a scenario to edit it. Select one or more scenarios before running the model.

Add, copy, and delete scenarios using these buttons.

Change the order in which scenarios are displayed.

Create a new blank scenario list.

Load or save a scenario list.

Show the current scenario filename.

Running the Model


Figure 3.2: The Scenario Editor (Input Tab)

Figure 3.3: The Scenario Editor (General Tab)

Filenames and file status are displayed here. Double-click an item to change the filename or location.

When a file is selected, its

description will be shown here.

Use the Browse buttons to identify input and output directories.

Use Set to match the output directory to the scenario name.

Enter a scenario

name.

Identify the scenario

directories.

A description of the scenario

can be entered here.

Choose assignment

settings.

The default settings are

appropriate for most uses.

Set the network year, data year, and individual alternatives.

Run for the MPO or expanded area.

Set speed feedback options.

Running the Model


Figure 3.4: The Scenario Editor (Output Tab)

Figure 3.5: The Scenario Editor (Advanced Tab)

Note: Advanced model parameters should not typically be changed.

Different model stages are listed

here. Files for the selected stage

are shown

When a file is selected, its

description will be shown here.

Filenames and file status are displayed here. Double-click an item to change the filename or location. Note: Files will be missing until the model has been run.

Different model stages are listed

here.

Tables, Parameters, or

Access Data (i.e., table names in the

access database) can be selected

here.

Available data is shown here. Some data can be edited directly in the grid. Arrays will be edited in a separate dialog. Subarray data can be displayed by clicking in a cell and selecting Edit.

This button will reset all parameters currently shown (including subarrays) to default values.

Running the Model


Figure 3.6: The Model Dialog Box

Running Selected Model Steps

The user interface can be set to run only selected model steps or sub-steps. To run only a single

step, click the “Stop after each step” checkbox in the main model dialog box. When this box is

checked, the selected step will be run, but subsequent steps will not. When this checkbox is

cleared, subsequent steps will run automatically.

To exclude certain sub-steps or to run only selected sub-steps, the dialog box shown in Figure 8

can be used. By clicking on the button to the left of each model step, the user can enable or

disable specific steps. The behavior of the “Stop after each step” checkbox is not changed when

sub-steps are enabled or disabled.

Figure 3.7: Sub-Steps Dialog Box

If checked, only the selected model

step will be run. If unchecked,

subsequent steps will be run as well.

Click on a model step to run that

step.

Sub-steps can be deactivated.

Utilities are be run from this area.

Check to create a Summary.xlsx file upon model completion

Debug mode disables error handling and allows steps to be run even if required riles are missing.

The Dashboard can be used to create maps of model results.

Running the Model


Running Speed Feedback

Speed feedback can be enabled from within the scenario editor. When enabled, speed feedback

will only be run if:

1. The model is not set to stop after each step and

2. The model is started from Step 1, 2, or 3.

Otherwise, the model will be run as if the selected scenario does not have speed feedback

enabled. When the model is run with speed feedback enabled, a file named “Feedback.txt” is

created in the model output directory. This file is updated as the model runs and contains a

history of the speed feedback convergence process. The file can be used to determine whether

speed feedback has converged successfully or if additional iterations are needed. Furthermore,

the file can be opened while the model is running to check speed feedback convergence progress

during a model run.

When performing alternatives analyses, it is often preferable to run the model without enabling

speed feedback. However, trip distribution patterns must still be consistent with a baseline

scenario (e.g., an existing plus committed model run). Running the travel model with speed

feedback enabled also requires considerably more time than running the model with speed

feedback disabled. The model can be run without speed feedback using speed feedback results

from a previous model run to produce consistent trip distribution results. To do this, follow the

steps listed below:

1. Perform a complete model run with speed feedback enabled.

2. Use the Copy Feedback Results utility to save resulting speeds to the input network file.

3. Create a new scenario that uses similar roadway and land use assumptions.

4. The new scenario should reference the same network year as the original run.

5. The new scenario may include network alternatives or changes to land use data.

6. Set the new scenario to run without speed feedback and without initializing speeds.

7. Run the new scenario.

Model Utilities - Input


4.0 MODEL UTILITIES - INPUT

The model dialog box includes several utilities that can be used to prepare model inputs. Some of

these utilities will only be available if all required input files for a scenario have been identified

and are present.

4.1 Edit Network Year

The model roadway network is designed to contain data for various distinct scenarios. This tool

will allow network years to be added or deleted and can be operated as described below.

1. Select a model scenario that references an input network. The referenced input roadway network will be modified.

2. Click the Edit Network Year button in the main model dialog box (Input tab); the dialog box shown in Figure 4.1 will appear.

3. To add a network year:

a. Select a year from the drop-down list.

b. Click the Copy button. The tool will make an exact copy of the selected year. If the Alternatives option is enabled, you will be prompted to select alternatives to be included in the new network year.

c. Attributes for the new network year can be modified by opening the network file and using the tools available in the TransCAD software.

4. To delete a network year:

a. Select a year from the drop-down list. Note the base year network cannot be deleted.

b. Click the Delete button. The tool will delete all data fields associated with the selected year.

Figure 4.1: Add/Delete Network Year Dialog Box

Model Utilities - Input


Network years can contain up to four digits. A recommended practice is to use a two to four digit

code formatted as YYXX.

Where YY represents the network year (e.g., 12 for 2012 or 40 for 2040) and XX is an optional

descriptor (e.g., 12A, 12B, 40A, 40AB).

4.2 Create Select Query

A select link or node query file (*.qry) can be created for a scenario using the Select Link/Zone

Query Builder provided with the TransCAD software. This toolbox, accessed from Planning

Assignment Utilities Select Link/Zone Query Builder, is explained in the TransCAD software

documentation. This tool interactively guides creation of a query file. It cannot be used to create

a select zone query based on a node selection set. To create a select zone query based on a node

selection set, use the Create Select Query tool using the following steps.

1. Add the attributes as needed to the input network node layer (e.g., use a subarea ID).

2. Create a scenario that references the modified input network and select this scenario.

3. Click the Create Select Query button in the main model dialog box (Input tab). The system will warn the user if an existing select link/query file is specified for the selected scenario.

4. Enter a name for the new select zone query.

5. Select the query method:

a. To or from: Track trips departing or arriving,

b. From: Only track departing trips, or

c. To: Only track arriving trips.

6. Enter a selection condition when prompted.

7. When prompted, choose whether or not to add an additional query to the query file.

Once the query file has been created, it can be viewed and edited using TransCAD’s Select

Link/Zone Query Builder and can be used as input to a travel model scenario.

4.3 Copy Feedback Results

This tool will copy speed feedback results from a completed model run to the input roadway

network file. Copying speed feedback results will allow a subsequent model run to produce trip

distribution results consistent with the completed model run, as described in the Running Speed

Feedback section.

Model Utilities – Transit


4.4 Update Input Network

This tool will update the link facility type themes displayed when the roadway network is first

opened. Link theme settings will be set to be consistent with the settings provided in the original

model network.

In addition, this utility will update the ID field on the roadway network node layer with the correct

TAZ number. This action is necessary when splitting TAZs.

4.5 Edit Network

This utility creates a map containing the roadway network and route system, and then opens the

network editing toolbox. This map is set up and formatted to facilitate making changes to the

roadway network layer. This utility automates the process of setting up a workspace to edit the

roadway network. The resulting map operates on the input network associated with the selected

model scenario.

5.0 MODEL UTILITIES – TRANSIT

5.1 Link/Verify Route System

This utility links a route system to a particular roadway geographic file and checks the route

system for errors. More information on this tool can be found in the Editing the Route System

section.

5.2 Edit Routes

The Edit Routes utility creates a map containing the roadway network and route system, creates

a temporary working “.net” network, activates the route system layer, and then opens the route

editing toolbox. This utility also links and verifies the route system identified in the selected

model scenario. The resulting map is set up and formatted to facilitate making changes to the

route system. This utility automates the process of setting up a workspace to edit the route

system.

5.3 Calibrate Constants

The Constant Calibration utility runs the mode choice model and compares results to a set of

mode targets stored in the model database. The utility then adjusts mode constants and re-runs

mode choice iteratively until model results are consistent with mode choice targets, or an

Model Utilities – Transit


iteration limit is met. The utility should only be run for scenarios where the roadway network,

route system, and socioeconomic data reflect conditions consistent with the mode choice target

values stored in the database.

This utility makes changes to the input database and should only be used when re-calibrating

the base year model. The model database should be backed up prior to running this utility.

Model Utilities – Maps and Reports


6.0 MODEL UTILITIES – MAPS AND REPORTS

The model contains mapping and reporting utilities that can be used to produce additional model

outputs and summary data. These tools, described below, will only be available if all selected

scenarios have been run successfully and read “done” in the status column. Some of these

utilities can only operate on one scenario at a time and will be disabled when multiple scenarios

are selected.

6.1 Create Performance Report

This tool will allow the user to create a standard summary report for all selected scenarios. The

user will be prompted to select performance report options prior to report creation.

6.2 Create Maps (Dashboard)

The Create Maps utility creates maps that display model results. The utility opens a new toolbox

and can only be opened when a single completed model scenario is selected. The toolbar allows

the user to specify a map type and then choose options described in Table 6.1 and Table 6.2.

Once settings have been chosen, the Create button will generate the specified map.

Table 6.1: Map Types

Map Type Description

Validation The validation map displays model volumes and traffic counts. Volumes are shown in thousands, with counts also shown in thousands, but placed in parentheses. Model results are shown on all links, while count data is only shown on links where validation traffic count data is available. If the highlight option is selected, a color-coding scheme will identify model data similar, higher, or lower than count data.

This map is only meaningful when created for a base year model run.

Volume The volume map displays model volumes in thousands. The user can opt to display daily, peak hour, or off-peak volumes.

LOS The LOS map displays a planning-level peak-hour level of service estimate based on 24-hour volumes.

Select Link/Node The select link/node map displays the results of a select link or node analysis. This map can only be created successfully if select link or node analysis is enabled for the selected model run.

Traffic Comparison The traffic comparison displays the differences between two model runs. When creating this map, the user will be prompted to select a scenario for comparison.

Volume/Capacity The volume/capacity map displays the volume to capacity ratio using a color theme. While similar to the LOS map, this map uses modeled volume and capacity data rather than a planning-level analysis.



Table 6.2: Map Options

Map Option Description

NCHRP If selected, the map will display NCHRP-255 adjusted volumes instead of raw model results.

Volumes If selected, the map will include traffic volume labels. If left blank, the model will not include labels.

Connectors If selected, the map will show centroid connectors. If left blank, centroid connectors will be hidden.

Highlight If selected, a validation map will differentiate between links where model results are similar to, higher than, or lower than traffic count data. This option can only be selected when creating a validation map.

Label Connectors If selected, volume labels will be plotted on centroid connectors. However, labels will only be shown in the Volumes option is also selected.

Label Local If selected, volume labels will be plotted on local streets. However, labels will only be shown in the Volumes option is also selected.

6.3 Process Turns

The travel model saves turn movement information for selected intersections during traffic

assignment routines. No calibration or validation process has been performed to ensure turn

movements produced by the travel model are reasonable or realistic. Raw movement data

should not be used directly for analysis, a utility is provided to adjust data using processes

defined in NCHRP-255. TransCAD also contains built-in utilities for estimating turn movements

based on link flows. These estimates can be used to get a general sense of activity at an

intersection. When using the built-in utility, turning movement counts should be compared to

base year model results as well as turning movement forecasts.

The Built-In Turn Movement Utilities

The built-in turn movement utility can be accessed after opening or creating a map that includes

traffic assignment results (e.g. in a joined view). To view estimated turn movement results, click

the intersection diagram tool in the main mapping toolbox: and then select a node. After

settings are entered in the dialog box, an intersection diagram will be created. For additional

details on operation of this function, see the TransCAD online help system.

Alternately, raw modeled turn movements can be viewed using the tool accessible from Planning

Planning Utilities Display Intersection Flows. Modeled turn movement volumes for AM and

PM peak hours are saved in “TurnsAM1.bin” and “TurnsPM1.bin.” Turn movements are only

saved for intersections with a value in the INT_ID node field. When saving turn movements, each

node with a value in the INT_ID field should contain a unique positive number.



Turn Movement Add-In

The NFR Model includes an intersection processing utility which can read and write data using

comma separated value (CSV) files in universal traffic data format (UTDF). Operation of the

intersection processing utility requires additional data and is only run for those intersections

identified by the INT_ID field on the node layer. All intersections with a value in this field can be

included in the analysis. This ID also serves as a link between the TransCAD network and

information contained in other databases, such as a Synchro network. For functions requiring

count data and to export data to in an external format, the INT_ID field on the node layer must

match the node ID of intersections in a turn movement count file and a Synchro network. The

turn movement processor is currently limited to intersections with three or four legs. To access

the turn movement add-in shown in Figure 6.1, click the Process Turns button on the main model

dialog box (Maps and Reports tab).

Figure 6.1: The Process Turns Dialog Box

Intersection Definition File

Load, create, or edit an

Intersection Definition file.

Save raw (unadjusted)

turn movements to

a CSV or HTML file.

Save turn movement

estimates to a CSV file.



All turn movement functions require an intersection definition file that identifies the

configuration of each intersection selected for analysis. A new intersection definition file can be

created from the turn movement dialog box, or a previously created definition file can be loaded.

Turn movement definition files reference INT_ID values and link ID values, so a new definition file

must be created after certain input file modifications.

Once an intersection definition file is created, it should be

verified for accuracy. For functions requiring existing traffic

count data, the intersection leg definitions must match

those in an input data file. Definition files should be

checked manually to ensure that the correct legs are

identified at each intersection. To do this, click the “Edit”

button after creating an intersection definition file. If

necessary, correct the intersection definition file by

adjusting the definitions of each intersection as shown in

Figure 6.2

Figure 6.2: Editing the Intersection Definition File

Intersection approaches are color-coded. The red leg is the northern approach.

The initial guess may not be correct. Here, the north and east legs are defined incorrectly.

Click on a button and then click on an intersection leg to define its direction.

Use the arrows to browse through intersections, or the Jump button to select an intersection by number.

The turn movements utility cannot process intersections with more than 4 legs or with diagonal legs. To overcome this limitation, all intersection approaches must be renamed as N, S, E or W in a Synchro network and 5-legged

intersections must be evaluated manually.



Unadjusted Turns

Unadjusted turn movements can be saved to a CSV file. This file can then be read using a

program such as Excel or can be imported to Synchro. For import to Synchro, intersection ID

numbers and approach directions must be consistent. When outputting adjusted turns for

forecast scenarios, unadjusted turns from a base year scenario are also required as an input file.

Adjusted Turns

The model can adjust turn movements using NCHRP-255 intersection procedures. Use the steps

described in this section to export adjusted turn movement data to a CSV file which can be

imported to Synchro.

1. Identify intersections in the TransCAD Network:

Enter the intersection ID into the INT_ID field in the node layer of a TransCAD network. If a separate network is to be used for the calibrated base year model run, INT_ID values must be entered into this network. The INT_ID field should be cleared for nodes or intersections not present in the Synchro network.

2. Run the base and forecast year travel model: The base and forecast year model scenarios should be run in full with INT_ID information present in both networks.

3. Create a base year intersection definition file: Use the Process Turns utility to create an intersection definition file. Ensure all intersection approaches are defined in a manner consistent with the Synchro file.

4. Export the unadjusted base year model turn movements: Save the turn movement data with an easy to remember name.

5. Create a CSV file containing observed turn movement data: This file must contain complete turn movement data for each intersection to be analyzed. The file can be created by exporting turn movement data from Synchro, or by modifying the unadjusted base year model turn movements file to contain turn movement count data.

6. Load or create a forecast year intersection definition file: In most cases, the file created for the base year can be re-used. If not, a new file must be created. If in doubt, use the Edit function to verify a loaded intersection definition file is correct.

7. Export the adjusted forecast turn movements: CSV files containing base year count data and base year unadjusted modeled turn movements must be referenced. Exported turn movements can be loaded into Synchro or a spreadsheet program for additional analysis.

Once these steps have been followed, an adjusted turns CSV file will be created, which contains

turn movement forecasts based on observed turn movement counts and travel model forecasts.

However, these forecasts are estimates and professional judgment should be used to interpret

the results. Where intersection configurations change or where turn movement count data is



suspect, manual intervention will be required. If more detailed information, such as a traffic

study, is available, this information should be used in addition to or instead of these planning

level forecasts.

Model Database


7.0 MODEL DATABASE

The model requires a large and varied set of input data for each model run. Each step of the

travel modeling process requires specific data items as inputs. The data is contained in three

primary places:

Spatial Data: The roadway line layer and route system contain the supply side information

used by the travel model. The TAZ layer is also input to the travel model, but zone data is not

stored directly in the TAZ layer.

Model Database: The model database contains socioeconomic data and other demand side

information used by the travel model. The database also contains model parameters such as

trip rates and other zonal data such as area type.

Scenario Manager: Some model parameters are stored directly in the scenario manager.

Aside from parameters accessible from the General tab in the scenario editor, this

information does not need to be changed in normal use of the model.

This chapter provides a detailed description of the data and parameters contained in the model

database.

7.1 Database Approach

The NFR MPO Travel Model relies on a large amount of data, numerous parameters, and lookup

tables. The TransCAD software uses a table format to store this information. The TransCAD table

format is relatively efficient, very stable, and allows for sufficient precision in storage of decimal

numbers. This format, Fixed Format Binary (FFB), has been used to store all data output from the

travel model. However, an Access database has been used to store the majority of data input to

the model. The Access format has been used rather than the FFB format for several reasons:

The TransCAD table format cannot be read or edited except with the TransCAD software;

The Access database can be used to store nearly all required input data for the travel model,

eliminating the need to manage a large number of input files containing data for various

model steps;

SQL queries within the Access software can be used to convert data from a human-readable

format into a format readily used by the travel model; and

The Access database is designed to manage multiple data scenarios within a single

consolidated database file.

Model Database


The model has been designed to support both network and data scenarios. Network scenarios

are stored in the TransCAD geographic line layer, while data scenarios are stored within the

model database. A nearly unlimited number of data scenarios can be maintained within a single

database, but in practice it may be useful to maintain different databases for different purposes.

For example, one database could be maintained for the regional planning process, while a

different database could be maintained for testing minor land use alternatives associated with

proposed development.

The database contains some information that is static (does not change when a different data

scenario is selected) and other data that is dynamic (varies by data scenario).

Static Data includes:

Roadway parameters (lookup tables by facility type and area type);

Household size and income disaggregation curves;

Trip generation rates (production and attraction rates);

Friction factors (gamma parameters);

Terminal times;

Mode choice parameters; and

Time of day parameters.

Dynamic Data includes:

Socioeconomic data at the TAZ level;

Other TAZ data (area type, parking cost, sub-region, etc.);

Regional bivariate data (household size and income);

Special generator data; and

External station data.

7.2 Database Interface

When opened, the model database will present the user with a request to enable Visual Basic for

Applications (VBA) macros. Once macros are enabled, the database interface form will appear.

This form provides automated management of data scenarios and guided access to key datasets.

The interface is annotated in Figure 7.1.

Model Database


To modify dynamic data for a specific data scenario, set the active scenario to the desired year

and open the scenario specific datasets from the main interface dialog box. Data can be edited

directly in Access. Alternately, data can be copied from Access and pasted into Excel. Once data

has been modified, it can be pasted back into the Access database.

Not all datasets can be accessed directly from the database interface form. Some datasets are

only edited during a model update and re-calibration and can be accessed only by opening the

data tables directly.

Figure 7.1: Access Database Form Interface

* All datasets contain expanded data regardless of the MPO/Expanded setting. This setting only changes

the amount of data shown.

The user interface can be used to copy dynamic datasets to a new data scenario, create a new

blank data scenario, or delete an existing data scenario. The dialog box that provides this

capability is accessed using the Manage Data Scenarios button and is shown in Figure 7.2. Once a

new dataset has been created, socioeconomic data, special generator data, and external station

These buttons will open data tables

containing dynamic datasets.

With the exception of EE data, these

tables can be edited.

Use these buttons to view or edit roadway lookup values or trip rates.

Use this button to add or delete data scenarios. The active scenario and a description are also shown in this section.

Set data views to show MPO data or expanded data*

Model Database


data can be modified for the new scenario. Bivariate data can also be edited, but does not need

to be changed in most cases.

Figure 7.2: Data Scenario Management

7.3 Database Tables

Information is stored within tables in the Access database file. A list of these tables and a

description of their contents are included in Table 7.1. For some tables, SQL queries are used to

convert data from a human-readable format to a format compatible with the model. SQL queries

are also used to filter dynamic datasets to show only data for the selected year.

All tables that contain model data are prefixed with the letter “a.” Queries based on tables use

the same name as the source table, but include a suffix consisting of an underscore and a number

(e.g., _1). Tables, queries, and forms prefixed with an x, y, or z are present only for use with the

program interface and are not listed in Table 7.1.

Table 7.1: Access Database Tables

Section Table/Query Name Description

Roadway Network

aRoadwayLookup Roadway parameters by facility type and area type

aRoadwayLookup_1 Roadway lookup table formatted for TransCAD

aRoadwayVariables List of variables contained in the roadway lookup table

Socioeconomic Data

aSEData Socioeconomic data at the TAZ level for all data scenarios

aSEData_1 Socioeconomic data filtered to the active data scenario and modeling area

aZoneData Contains additional TAZ data for all data scenarios

Model Database


Section Table/Query Name Description

aZoneData_1 Additional TAZ data filtered to the active data scenario and modeling area

Household Models

aDisaggIncome Household income disaggregation curves

aDisaggSize Household size disaggregation curves

aDisaggWorkers Household worker disaggregation curves

aRegBivarPct Regional bivariate distribution of households for all data scenarios

aRegBivarPct_1 Regional bivariate distribution of households filtered to the active data scenario and modeling area

Trip Generation

aProductionRates Production rates

aAttractionRates Attraction rates

aSpecialGen Special generator values for all data scenarios

aSpecialGen_1 Special generator values filtered to the active data scenario and modeling area

aTripRateFactors Trip rate factors by sub-region

aTripRateFactors_1 Trip rate factors by sub-region filtered to the active modeling area

aTripRateFactorsAT Trip rate factors by area type

External Trips aEETrips External/External trip table for all data scenarios

aEETrips_1 External/External trip table filtered to the active data scenario and modeling area

aIETrips Internal/External and Internal/External trip table for all data scenarios

aIETrips_1 Internal/External and Internal/External trip table filtered to the active data scenario and modeling area

Trip Distribution

aFrictionFactors Friction factor gamma parameters

aFrictionFactors_1 Friction factor gamma parameters filtered to the active modeling area

aTerminalTime Terminal time values by area type

Mode Choice aExternalTransit External station transit values (Caution: use with care)

aExternalTransit_1 External station transit values filtered to the active data scenario

aModeCoefficients Mode choice model coefficients

aModeConstants Mode choice model alternative specific constants (ASCs)

aModeTargets Mode choice target values (for use in mode choice calibration)

Assignment aLoadingFactors Traffic assignment loading factors

aLOSCap Daily planning-level level of service capacities

aPCE Passenger car equivalent values

aPeriodFactors Directional daily to sub-period factors

aPeriodFactors_Assignment Period factors to convert from peak/off-peak to traffic assignment periods

aPeriodFactors_Distribution Period factors to convert from daily to peak/off-peak

Transportation Networks


8.0 TRANSPORTATION NETWORKS

The NFR Model requires both roadway and transit networks to operate. These networks are

described in detail in the model documentation. To work with the roadway and transit networks,

it is important to understand the connections and relationships between different components of

the transportation networks and the TAZ data.

8.1 Transportation Network Components

The transportation network is made up of the components listed below:

Links: Links are stored in the line layer in the roadway geographic file. Different types of links include: o Active roadway links: Each roadway segment is represented by a link (or line) in the

roadway network layer. o Inactive links: The roadway geographic file can also contain roadway and non-motorized

links inactive for a given scenario. These links are ignored by the model. o Centroid Connectors: Centroid connectors attach centroid nodes to roadway links

Nodes: Nodes are attached to links. Types of nodes include: o Centroids: Centroid nodes connect to the model database and the associated

socioeconomic data. These nodes are identified by a non-zero value in the “ZONE” field on the node layer. Zone numbers must be unique to each zone, but do not necessarily need to be sequential.

o External Stations: External stations are similar to centroids, but are located on the model boundary. Database information for external stations is maintained in a different format.

o Park-n-Ride Nodes: Park-n-Ride nodes are located at locations where trip-makers can transition from a personal vehicle to a transit vehicle. Park-n-ride nodes cannot be centroid or external station nodes and must be matched with at least one transit stop.

o Other Nodes: All other nodes are used solely to define link start and end points. These nodes may be located at intersections, where centroid connectors connect to roadway links, or mid-block.

Routes: The TransCAD Route System represents transit routes. Routes start and end at nodes and must traverse roadway links in between. Routes use information stored on the roadway links, such as freeflow and congested travel time.

Transit Stops: The transit stop layer is attached to the transit route system. Transit stops provide a connection between link and node layers, used to represent access to transit (via the walk or drive modes). All stops must be placed on a transit route and must be placed at a network node. o Note: TransCAD does not automatically enforce consistency between the node and stop

layer. It is important to follow the route system editing guidelines provided later in this document.



8.2 Example Transportation Network Application

The example that follows includes a complete description of the process that would be used to

add a roadway segment to the network and modify a transit route to traverse the new link. The

example adds a new connection between Harmony Road and SH-392 parallel to Taft Hill Road,

and Shields Street. The connection is added as a four-lane principal arterial.

Note: This example is presented for illustrative purposes only and is not necessarily consistent

with NFR MPO planning documents.

Before we Begin: Make a Backup Copy

This example modifies the model input data. Before starting, it is advised the user make a

complete copy of the C:\NFR Model v4\Input folder. Once the example exercise has been

completed, the user can restore the original files from the backup copy.

Part 1: Prepare Workspace

Begin this section by starting the TransCAD software program. Once TransCAD is open, perform

the following actions:

1. Start the model dialog box from Tools Add-Ins NFR Model. 2. Make sure a valid scenario is selected in the Scenario Toolbar.

a. If the model was installed directly from the installation media, the included base year scenario should work correctly.

b. If the model data was not installed to the default location, it may be necessary to re-specify the scenario input and output directory.

3. From the Utilities section of the dialog box (bottom section), select the Input tab and click the Edit Network button. a. This action will create a new map showing the roadway network and route system. b. The NFR Model dialog box will be closed.

4. Verify the intended network file has been loaded into the map.

a. Click the map layers button ( ) in the TransCAD toolbar. b. In the window that appears, verify the NFR NETWORK entry is selected. c. Verify the Geographic File named at the bottom of the window is indeed the

geographic file to be edited. i. Note: If the wrong file is listed, edit the selected scenario to reference the correct

input network file. d. Click Close.

5. Use the zoom tool ( ) to zoom to the vicinity of the Harmony Road between Taft Hill Road and Shields Street.

6. Verify that the Map Editing toolbar is present in the workspace. If it is not, it can be enabled from the TransCAD

toolbar ( ) or menu (Tools Map Editing Toolbox).



Part 2: Add New Roadway Link

Once the workspace has been set up, use the following steps to add the new roadway segment:

1. Review the area where the new roadway will be added. Observe: a. The new roadway will start and end at existing nodes, and b. The new roadway will cross two existing roads, creating new intersections.

2. Because the new roadway will cross and connect to existing facilities, it will be necessary to: a. Check for pre-existing nodes where the new link will cross existing roadways, b. Split existing facilities in cases where a node is not already present, and c. Create the new roadway segment in three steps creating three links.

3. Add the first segment of the new link:

a. Select the Add Line tool ( ) from the Map Editing Toolbox. b. Click once on the node on the north side of the new segment along Harmony Road,

then c. Double-click on the roadway link (Trilby Road) where the new link will intersect.

d. Click the green light ( ) on the Map Editing Toolbox to save the new link to the line layer file and create an undo point.



Note: This action will split the roadway link to the south into two separate links and will retain important attributes

on both halves. It is a good idea to verify all important attributes have been retained on both halves of the

split link until the user has become comfortable with the network editing process.

4. Add the second segment of the new link:

a. Select the Add Line tool ( ) from the Map Editing Toolbox. b. Single-click on the newly created node, c. Single-click as needed to create shape points along the new link, and then d. Double-click on an existing node along Shields Street to add the second segment of

the new link.

e. Click the green light ( ) on the Map Editing Toolbox to save the new link to the line layer file. When the edit is saved, TransCAD will create an undo point, allowing the network modification to be reversed with the undo command.

1 – Single-click on the existing node

2 – Double-click on Trilby Road to split the link and create a new node.



5. Add the third segment of the new link:

a. Select the Add Line tool ( ) from the Map Editing Toolbox. b. Single-click on the existing node along Shields Street , c. Single-click as needed to create shape points along the new link, and then d. Double-click on an existing node at College Avenue and SH-392 to finish the new link.

e. Click the green light ( ) on the Map Editing Toolbox to save the new link to the line layer file and create an undo point.

1 – Single-click on this node from step 3

2 – Single-click to create shape nodes

3 – Double-click to finish the line at an existing node on Shields Street



6. Refresh the route system: a. Set the active map layer to Route System b. If prompted to update the route system, click Yes. c. Set the active layer back to the NFR NETWORK layer

Note: This step corrects any inconsistencies between the roadway line layer and route system layers

that may have been introduced by modifying the roadway line layer.

1 – Single-click on this node from step 4

2 – Double-click to finish the line at an existing node



Part 3: Edit the Roadway Segment

The new roadway links do not initially contain any data. Attributes must be added to the new

links using the following steps.

1. Identify a nearby link (a “source link”) with the same facility type and area type as the new link.

2. Click the Edit Line Attributes tool ( ) from the Map Editing Toolbox. 3. Copy attributes from the source link to the new link:

a. Click on the source link, b. Hold shift, then click on each new link,

c. In the window that appears, right-click in the first column and select Copy Values. Note: You may need to resize the window to see the data for the source link. The column with source link data should be the only column that contains values.

1 – Click on the source link

2 – Shift-click on each target link





d. Replace the street name for the new links by editing the values for Local_Name in the second three columns. Clear out any data in the Street_Name field. Take care not to modify the name of the source link.

e. Click the green light ( ) on the Map Editing Toolbox to save the updated attributes and create an undo point.

4. Modify attributes so this link will only be active in specific scenarios:

a. Use the standard information tool ( ) to edit attributes for the three new links. Click on one link, then shift-click on the rest.

b. Copy 2012 (i.e., *_12) attribute values to the alternative link value attributes (use Ctrl-C and Ctrl-V, or right click to select copy and paste). In most cases, only the fields shown in the image below need to be copied.



c. Select an alternative number (e.g., 9999) and enter the value in the ALT field

d. Clear values from the base year attributes and from other network year attributes as

desired. In this example, clear all attributes for all sets of network attributes that do not end in _AL. When multiple cells are highlighted, the quickest way to clear them is to right-click and Clear.

Copy

Clear for All Years



e. Check all remaining attributes, paying particular attention to count data. In this

example, it is recommended all count fields are cleared since the link does not exist in the base year.

i. Clear original count data from fields such as LAR_2010CNT and FC_2011CNT. ii. Clear summarized/processed count data from the fields shown below.

iii. Also clear the DO_NCHRP field so NCHRP-255 volume adjustments are not applied.

Part 4: Create a New Model Scenario

Once roadway edits are complete, the user can create a new model scenario that includes the new alternative. The steps required to do this include:

1. Create a new scenario that includes the new roadway alternatives: a. Close all files and windows in TransCAD (e.g., File Close All). b. Start the NFR Model dialog box from Tools NFR Model. c. In the Scenario Toolbox, make a copy of the base scenario.

2. Edit basic scenario information. a. Scenario Name: Base 2012 Alt 9999 b. Input Dir: No change (e.g., C:\NFR Model v4\Input\) c. Output Dir: Reference a new folder (e.g., C:\NFR Model v4\Output\Base 2012

Alt9999). 3. Input Tab – No changes at this time. 4. General Tab:

a. Click Alts under Scenario Settings. b. Move alternative 555 to the right side of the window. c. Make sure Run Speed Feedback and Initialize Speeds are not checked.

5. Output Tab – No changes at this time. 6. Click OK when done to exit the Scenario Editor.

Clear Values



Part 5: Realign a Transit Route

To demonstrate the process of modifying the route system, this example includes realignment of

an existing transit route to use the newly added roadway. Detailed route system editing

guidelines are also provided later in this guide.

Warning: This example is performed in a separate copy of the route system. See the technical

documentation for information on use of a master route system.

1. Make a copy of the route system: a. From the model dialog box, select the Transit Utilities tab in the Utilities section. b. Click the Edit Routes button to close the dialog box and open the route system in a

map. c. Select Tools Geographic Utilities Geographic File from the TransCAD menu. d. Click the Copy button. e. Save the copy of the route system using a new name (e.g., NFRRoutes2009Alt555).

2. Edit a scenario to reference the route system copy: a. Close all files and windows in TransCAD (e.g., File Close All). b. Start the NFR Model dialog box from Tools NFR Model. c. In the Scenario Toolbox, double-click on the desired scenario (e.g., Base 2009 (Alt

555) d. Double-click the Routes item in the input file list. e. Select the new alternative route system. f. Click OK in the Scenario Editor to return to the model dialog box

3. Open a map to edit the route system: a. From the model dialog box, select the Transit tab in the Utilities section. b. Make sure the new scenario referencing the route system copy is selected. c. Click the Edit Routes button to close the dialog box and open the route system in a

map. d. Verify the Route System Toolbox has appeared on the screen. e. Zoom the map to the vicinity of the new links

added earlier in this example. 4. Verify the intended route system file has been loaded

into the map.

a. Click the map layers button ( ) in the TransCAD toolbar.

b. In the window that appears, verify the Route System entry is selected.

c. Verify the route system file named at the bottom of the window is indeed the route system to be edited.

i. Note: If the wrong file is listed, check the selected scenario and make sure it references the correct input route system.

5. Add a new route to use the new links:

a. Use the Select tool ( ) on the Route System toolbox. b. Click on the node at the intersection of Harmony Road, and Lemay Avenue.



c. Click on the nodes along the roadway links as shown in the figure below and double click at the intersection of Centerra Parkway and Crossroads Boulevard.

d. This will prompt a new window asking for the route name. Type in “Route Centerra”

e. Select a new route alignment as shown in the example below.

f. The new route will be shown as a black line, two black dots, one each at the start and end of the route.

1 – Click where the route will begin

2 – Click on several points along the new alignment; make sure to click on nodes.

2 – Click on several points along the new alignment; make sure to click on nodes.

3 – Double-click at the

location where the route will

end



g. Click the green light ( ) on the Route System Toolbox to save the new route. When the edit is saved, TransCAD will create an undo point, allowing the route system addition to be reversed with the undo command.

h. This will add the route to the Route System as shown in the figure below.

6. Add stops to the new Route:

a. Use the Select tool ( ) on the Route System toolbox. b. Click anywhere along the new Route Centerra. c. If prompted, select Route Centerra.

d. To add stops, use the zoom tool ( ) to zoom close to the intersection of Harmony Road and Lemay Avenue where the route starts.

e. Click on the tool ( ) on the Route System toolbox to add stops and click on the node where the route starts.

New Route added to the route system

New Route added to the route system



f. Click the pan tool ( ) and pan along the route and add more stops at nodes where necessary.

g. Click the green light ( ) on the Route System Toolbox to save the new stop placement. When the edit is saved, TransCAD will create an undo point, allowing the stop addition to be reversed with the undo command.

Reminder: Refer to the Editing the Route System section of this document when choosing where to

place stops.

7. Verify the Route System: a. Close all files and windows in TransCAD (e.g., File Close All). b. Start the NFR Model Dialog Box c. Click the Link/Verify Route System button under the Transit Utilities tab.

i. Select the modified route system

Zoom VERY close to the node and add the stop on the node

Stop placement at nodes along the route



ii. Select the roadway geographic file associated with the route system iii. The utility will ask about checking for disabled links; select No. iv. Note: The route system uses links that are disabled unless a specific alternative is

selected, so the disabled links will fail. It is OK to allow this check and observe the results.

d. If the verification step fails or produces a warning message, carefully review the route system and read all warning messages the utility produces.

8. Verify the Route System – Stage 2 (Optional) The route verify tool checks for many possible route system problems, but some errors cannot be identified until the model is run. After making route system edits, the following additional steps are recommended: a. Start the NFR Model dialog box. b. Select a scenario that references the modified route system. c. Un-check the Stop after Each Step option. d. Run the first model step (1 – Prepare Networks). e. If the model run fails, there may be an error in the route system.

i. Review the resulting Log.xml file – it may provide useful troubleshooting information.

ii. If the model run succeeds, the route system is probably valid. The user is advised to review the Log.xml file and Report.xml file to check for meaningful warnings.

Part 6: Run the Model

Once these steps are complete, the model should be ready to run. Attempt to run the newly

created model scenario in full. If the model produces an error message, verify all input data was

created, modified, and referenced properly.

Working with Transit Data


9.0 WORKING WITH TRANSIT DATA

TransCAD Route systems must be created and maintained very carefully to ensure the TransCAD

Pathfinder builds reasonable and intuitive paths. Incorrect route system coding may produce

error or warning messages, but warning messages may only appear in the TransCAD log or report

file – without producing any obvious warning message from within the software. In some cases,

incorrect route editing will not result in any warning or error message, but will cause TransCAD to

build incorrect paths. This chapter provides general guidelines and recommendations for route

system editing in TransCAD.

9.1 Updating the Route System after Roadway Layer Changes

The TransCAD route system is based on the roadway network geographic file or the street line

layer. Because the route system relies on the roadway network, it is important to carefully

maintain the linkage between these two files. As a starting point, the user should always ensure

the route system is correctly linked to the roadway network and the route system is present in

the map when adding, deleting, splitting, or joining links in the roadway network.

Maintaining Route System Integrity

Because the route system is directly linked to the roadway network, TransCAD must modify the

route system any time a change is made to the roadway network layer. This is particularly

important if a roadway link traversed by a transit route is split, moved, or joined to another link.

When this happens, TransCAD will update the route system data to account for the change. The

easiest and least error-prone method of updating the route system is to add it to the map prior to

modifying the roadway line layer. After modifying a link traversed by a route, the user must set

the route system as the active layer to cause TransCAD to update the file.

If a user edits the roadway layer while the route system is not present in the map, TransCAD will

update the route system the next time it is opened. This update takes place even if none of the

modified links are traversed by a transit route. To ensure a route system is up to date, the

following procedure should be used regardless of whether the route system was present in a map

during network edits:

1. Close all files in the TransCAD program. 2. Run the Link/Verify Route System utility.

a. If this utility fails, continue to Step 3 anyway. 3. Open the route system in TransCAD.

a. Verify the correct line layer was opened automatically to support the route system. 4. Close all files.



5. If the Link/Verify Route System utility failed in Step 2, run the utility again. If the route system verification still fails, the route system must be repaired manually. (This is uncommon and will typically only occur if the guidelines in this section are not followed).

If multiple route systems are based on a roadway network file, it is important to perform the

steps listed above for each route system individually after making changes to the roadway

geographic file. When making major modifications to a geographic file, it is preferable to update

all route systems periodically during the editing process rather than waiting until all roadway

edits are complete.

It is only necessary to follow the guidelines specified above when splitting, joining, adding, and

deleting links from the roadway network. The steps above are not necessary when modifying

attributes of existing links.

9.2 Route System Link and Verify

Prior to making any changes to the route system or

roadway network, it is good practice to link the route

system to the roadway network and verify the route

system’s integrity. This can be done by using the

Link/Verify Route System utility available from the main

model dialog box. When activated, the utility will ask the

user to identify a route system, then the corresponding

roadway network file. The utility will link the selected files

and then check for errors in the route system. If the utility

is not available, this can be accomplished from the

TransCAD menu by using Route System Utilities Move, then Route System Reload, then

Route System Verify.

9.3 Editing the Route System

The route system can be edited with the Route System Editing Toolbox. However, this toolbox

requires a network (file with a .net extension) file as well as a geographic (file with a .dbd

extension) file. Prior to opening the Route System Editing Toolbox, create a working network as

follows:

1. Open the route system and verify the correct line layer has been opened with it. 2. Set the line (roadway) layer as the active layer. 3. Create a new network from Networks/Paths Create. 4. Save the network using a generic name (e.g., net.net). 5. Use the default network settings.

NOTE: A common mistake is to accidentally select the route

system stop layer (a “dbd” file) instead of the roadway network

layer. If this is done, the Link/Verify utility will not make

any changes to the route system, but will show an error message

instead.



After the network file has been created, the route system can be edited. The Route System

Editing Toolbox is activated by setting the route system as the active layer and then selecting

Route Systems Editing Toolbox from the TransCAD menu.

The TransCAD documentation provides detailed guidance on route system editing tools. Some

additional guidelines are provided here to ensure route systems will work properly.

Route stop problems are usually reported in the Log file that is generated during the first model

step. If the route system has been modified in any way, this file should be inspected for warnings

and errors. However, the log file will not indicate all possible problems, some of which may result

in flawed or illogical paths.

Route Direction

All routes are coded directionally from start to finish. If a route traverses a street more than once

(e.g., out and back along the same corridor), it must be coded to travel out and then back. A

simple way to think of this process is to code the route exactly as it is driven. There are two

approaches available to represent routes that travel out and back along a corridor:

1. Separate routes for each direction: This approach includes a separate route for each direction, such as “Route 1 EB” and Route 1 WB.”

2. Single route for both directions: This approach includes a single route that travels out and back, starting and ending at a single point.

For routes which travel in a loop pattern, it is typically best to code the route as a single route.

Stop Placement

Stops must be placed on the route system according to a specific set of rules. Incorrect stop

placement is the most common source of transit network related model crashes, warning

messages, and silent errors that can invalidate model results. This section includes a list of

guidelines regarding proper stop placement. Many of these guidelines have specific and

WARNING: Route stop problems do not always cause the model to crash. Problems are often reported in the Log file generated during the first model step. If the route system has been modified in any way, this file should be inspected for warnings and errors. HOWEVER: The log file will not provide warnings about improper route coding which may cause incorrect model results.



important exceptions, so it is important to consider the entire set of guidelines prior to editing a

route system in TransCAD.

Route stops should be placed on routes at all locations where walk access to transit is available.

Stops are not needed at nodes where walk access cannot be achieved or where other nearby

stops on the same route can be reached more quickly from all nearby zones.

Place Stops at Nodes

While TransCAD will allow the user to place stops at any location along a route, the pathfinding

algorithms used for mode choice modeling require each route stop to be located at a node in the

roadway geographic file. TransCAD does not “snap” route stops to line layer nodes, but instead

internally links each stop to the closest node. If any stops are placed too far from the nearest

node, the travel model will produce a warning (in the Log file) and the stop will be ignored. This

type of error may not cause a model crash or a visible error message.

Multi-Pass Stops (Mid-Route)

TransCAD’s path building algorithms allow one and only one stop for each time route passes a

node in the geographic file. This means only one stop is allowed at each node for routes that do

not double back or traverse a segment multiple times. For routes which do traverse a corridor

multiple times, TransCAD will allow multiple stops at a node. Multiple stops located at a single

node must be properly associated with the first, second, etc. route pass. In most cases, a stop

should be placed for each pass at all nodes along a two way segment.

To correctly create multiple stops at a node, use the following steps:

1. Select the route for editing and zoom in to the a node where a multi-pass stop is desired;

2. Use the Add a Stop tool ( ) to add a stop at the node, choosing Pass 1 when asked. 3. Use the Add a Stop too to add a second stop at the same node, choosing Pass 2 when

asked. 4. Verify the stop appears with a number 2 as shown in the example below.

Route Start/End

For all routes, stops must be placed at the beginning and end of the route. For loop routes or out-

and-back routes coded as a single route, this requires multiple stops at a single node. For out-

and-back routes, correct stop placement can be achieved by treating the start/end point as a

mid-route stop. For loop routes, stops cannot be placed as first and second passes. In such cases,



two stops should be placed as shown below. In this example, the scale has been set so the stops

shown are placed approximately 6 inches (in map units) from the node where the stop starts and

ends. At this scale, some versions of TransCAD may snap a stop to a node, in which case it is

advised to move the stop so it is slightly offset from the node.

WARNING: Failure to code loop routes as shown may result in improper transit paths, but will

not produce any warning or error messages in TransCAD.

Mid-Route Turnaround

At a point where a route reverses, but does not start or end, only one stop should be placed. If

two stops are placed at a mid-route reversal, the model will not work correctly and may fail to

run. Correct placement of a stop at a mid-route turnaround is shown below.

Route Start/End

First stop

Last stop

Only one stop should be placed at this location.



One-Way / Two-Way Transition

At locations where a route transitions from a loop configuration to an out-and-back

configuration, a two-stop pass must be placed on the two-way portion of the stop at a location

very close to the node. Additionally, at least one extra stop must be present on the loop portion

of the route. An example of a correct and an incorrect stop placement is shown below.

Correct Incorrect

NFR Regional Travel Model – User's Guide - NFRMPO

Documents

Transcript of NFR Regional Travel Model – User's Guide - NFRMPO