FORMULAS OF TRAFFIC AND STREETS (RE)SHAPING, FOR A NEW QUALITY OF LIVING AND TRAVELS SAFETY IN...

CONFERINŢA ŞTIINŢIFICĂ INTERNAŢIONALĂ Cercetare, Administrare Rutieră, “CAR 2013”

2013 Bucureşti, 4-5 iulie 2013

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FORMULAS OF TRAFFIC AND STREETS (RE)SHAPING,

FOR A NEW QUALITY OF LIVING AND TRAVELS SAFETY

IN CITY AREAS

Associate Professor Ph.D. arch. Mihaela Hermina NEGULESCU

,,Ion Mincu’’ University of Architecture and Urban Planning, Bucharest;

[email protected]

Abstract

The priority accorded to automobility, the unconditional adaptation of cities to car flows that

constantly increased, for several decades, had a negative impact on the natural and urban built

environment, leading to an unbalanced and unsustainable use of public space resources.

Moving or stationary vehicles "confiscated" streets and squares - former community’s spaces,

with aesthetic attributes - and turned them (only) into road infrastructure, concrete urban

forms in which the quality of living and travels safety thus decreased. In this dynamic and

despotic urban geography of traffic flows, city areas, addressed only as Origin and

Destination, have lost their significance of places and territories with social and cultural

substance, with specificity and heritage value. The current paradigm shift in urban mobility,

according to the logic of sustainability, aimed at (re)balancing accessibility requirements with

those of living environment and urban heritage protection. Traffic flows are those that, still

answering the accessibility requirements, have now to be adapted to the city areas they are

passing through, taking into account their morphological, functional, historical and

sociological characteristics. The present paper proposes models of streets and traffic flows

adaptation to the new demands of city areas: 1. a new type of streets classification, through

the reconsideration of the ratio between theirs functions of traffic infrastructures and living

spaces, as tool for differentiating urban character of streets; 2. modal shift and bypass arterial

systems for city areas sensitive to motorized traffic impact.

Key words: streets classification, traffic, city areas, quality of urban living

mailto:[email protected]



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1. NEGATIVE IMPACT OF UNDIFFERENTIATED INSERT OF

MOBILITY IN CITY AREAS

The priority accorded to automobility, the unconditional adaptation of cities to

car flows that constantly increased, for several decades, had a negative impact

on the natural and built environment, and led to an unbalanced and

unsustainable use of public space resources. The streets became only

infrastructure for traffic and transport, gradually losing their vocation of public

space for communities and social interaction, and also their attribute of urban

landscape whose aesthetics is a component of quality of living. With car

supremacy in urban settlements, with the increase of motorized traffic – as

volumes and speeds, with the excessive parking on public space, with the

decrease and even disappearance of pedestrian places or sidewalk narrowing,

comfort and safety of travels drastically decreased, in big cities.

[SAFENET,2012]

In this dynamic and despotic geography of flows, city areas, approached only as

origin and destination, have lost their quality of lived places and territories,

meaning spaces with social and cultural substance, with specific patrimonial

value.

2. A NEW LOGIC OF TRAFFIC FLOWS INSERTION IN CITY

AREAS

The current change of urban mobility paradigm, according to sustainability

logic, aims at (re)balancing the requirements of accessibility and those of

protecting the living environment and urban heritage. Flows are those which,

Figura 1. Streets turned into roads and parkings for cars



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still answering accessibility needs, have now to be increasingly adapted to city

areas through which they pass, taking into account their functional,

morphological, historical and sociological characteristics.

The focus moves from planning and adaptation of streets networks in favor of

motorized traffic flows (enlargement of streets and / or carriageways to the

detriment of other uses of the street) to "adaptation of flows to the city areas

they pass through and serve" according to the principle "the right mobility in the

right place ". Automobility loses its sovereignty, while the requirements for a

more pleasant urban living environment and for the enhancement of city areas

with valuable historical and architectural heritage states the strong need for

remodeling urban mobility to promoting non-motorized modes of travel - less

invasive, clean and with lower potential for injury -and other travel modes less

consumer of space resources: collective public transport (0 parking on public

space), motorbikes etc.

This new concern for differentiated and non-conflicting insertion of flows in

urban zones [Negulescu, 2011] stated categorically in the last decade,

crystallizing, through many European urban experiments, several methods of

intervention in city areas sensitives to motorized traffic effects. This methods

mainly concern: 1. Integrated remodeling of mobility in areas sensitives to

motorized traffic (residential, commercial, recreation, etc.) and with priority in

those with higher architectural, urbanity and communitary value, such as, for

example, the historic central zones of cities (see section 3); 2. Reshaping urban

streets for differentiated (re)harmonization of their two main functions: " traffic

infrastructure" and "living space", focusing on one or on the other of functions

according to the characteristics and requirements of city areas they belong to or

passing through, and to the type of accessibility they have to provide (see

section 4).

3. METHODS FOR REMODELING TRAFFIC WITHIN ANCIENT

CITY AREAS, WITH INCREASED REQUIREMENTS FOR

LIMITATION OF AUTOMOBILITY

Acute dysfunctions generated by the uncontrolled development of traffic occurs

in old city areas with irregular and narrow streets networks, settled before the

emergence and spread of the automobile. Of these, particularly in cities with

radial-concentric structure without complete road rings, the historical urban

centers are those who generally are polarizing the most and serious issues:



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traffic congestion, noise and chemical pollution, excessive occupying of public

spaces by moving or stationary cars, the deterioration of the urban landscape and

depreciation of architectural heritage.

In such areas, aesthetic and functional quality of public spaces is an important

requirement and a prerequisite for social, touristic and economic attractiveness.

Therefore, it is necessary to adopt packages of integrated measures for reshaping

mobility, essentially aiming at reducing automobility and the presence of

vehicles in public space and cityscape. These areas with high sensitivity to the

effects of motorized traffic should preferably be areas with limited traffic (as

volume and speed), shared-space areas and/or, in some cases, partially or

entirely car-free zones. For this, many cities (such as Strasbourg, London,

Munich etc.) designed integrated mobility policies for their central areas, with

packets of coherent and consensual measures, of different kinds and from

different domains: transportation, traffic, roads, urban planning, ecology ,

economics, socio-cultural, legislation, etc..

Referring to the prioritary objective of limiting motorized flows penetration in

the areas that have to be protected from excessive automobility, two types of

major measures should be considered:

1. Deviation of a large amount of motorized flows which use to transit a

“traffic sensitive area" without serving the activities located in it, on a

detour road /“ring-road” on the perimeter of the area, a boundary road

that has to be identified/ remodeled/ completed or created, according to

the specific urban context. (see figure 2)

2. Change of modal split within the protected area, through intermodal hubs

located on the boundary road of the area at the intersection with the

streets that penetrate inside it. (see figure 3). Intermodal hubs must relate,

in comfortable conditions of transfer, park & ride parkings, bike @ ride

parkings with public transport stations (TP) and, in some cases, with a

public bicycle service, car-sharing and/or taxi stations.

In this way, within the targeted areas can be reached the goal of considerably

reducing the modal share of automobility, in favor of non-motorized,

environmentally friendly travel modes (cycling, walking) and public transport

(PT), and the goal of creating premises for a complex urban regeneration.

Valuable public space resources can be thus recovered for the rehabilitation of

streets and squares, for creating pedestrian streets and areas, with safe and



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pleasant ambience, auspicious for the development of business, recreational and

touristic activities.

Figure 2. Main measures aiming at reducing motorized traffic in city areas

sensitive to its effects; Source: the author

Large and

numerous

dysfunctions in

areas with old

urban tissue and

with limited

resources of free

space

UNDIFFERENTIATED

INSERTION OF

AUTOMOBILITY IN ALL

URBAN AREAS

1.

MOBILITY ADAPTATION TO EXIGENCIES OF

URBAN AREAS WITH ANCIENT TISSUE AND / OR

SENSITIVE TO MOTORIZED TRAFFIC (central cities

areas, residential, commercial, recreation areas etc.).

2.

BYPASS-

DEVIATON

of transit traffic

MODAL SHIFT

of traffic

within the area,

through nodal hubs

with park&ride

Lower

disfunctions

A

B

(Re)sharing of public

space – reducing of

roadways and surface

parking areas for

improving pedestrians

infrastructure and

landscaping



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Figure 3. Intermodal hubs – with park&ride facilities- on the new urban axis

Buzeşti-Berzei-Uranus, for changing the modal split in the historic central area

of Bucharest city; Source: NEGULESCU, 2011

3. A NEW STREETS CLASSIFICATION FOR THE DIFFEREN-

TIATION OF THEIR URBAN CHARACTER

Also for improving urban ambience and safety in public spaces, in European

urban practice emerged a new tool for differentiation of streets character, used

for a more harmonious insertion of mobility in urban tissues and territories of

communities: classification of streets on the criterion of prevalence in the ratio

between their functions of “infrastructure for traffic” and “living space” -

community space with landscape attributes.

Mobility (as infrastructure, moving or stationary vehicles) transits and serves

different types of areas, with diverse structures, morphologies, spatial resources,

architectural values and with different requirements regarding a harmonious

insertion of traffic and its infrastructure within urban tissues and landscapes

(see.fig.4).

Intermodal hubs

including park&ride

facilities located at the

intersection of Buzeşti -

Berzei-Uranus urban

axis with the penetrant

roads into the central

core of the city

(Kogălniceanu Av.,

Calea Ştirbei Vodă,

Mircea Vulcănescu

Av.) as “gateways” of

that area, with priority

for public transport,

bicycle and pedestrian

travels and with

limited, selective acces

of cars

Public Transport travels

Walking and cycling

Individual motorised

travels

The historic central core

of the city

Simple or complex

intermodal hubs

Pedestrial ways and

squares (with bike

lanes) Parkings, with higs

tariffs

park&ride and

bike&ride with low

tariffs

Public Transport

stations



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Not only the functional role must influence the morphology of a street

(especially its transverse profile) but the characteristics and conditionings of the

urban area passing through. More the area is valuable in terms of architecture

and / or higher demands of living quality, more attention will be given to

modeling urban streets and markets as "living spaces", community spaces with

landscape aesthetic attributes.

Figure 4. Changing the character of street sequences according to

characteristics and exigencies for good living environment of different city

areas; Source: the author

Urban character of streets, wholly or for some of their sequences, as a result of

the report between their two major functions - infrastructure for traffic and

living space- should therefore be better differentiate according to:

their function in urban road network (major arteries: 1.2 / lower category

roads:3,4)

their location relative to city areas / neighborhoods: inside or outside-on

the perimeter of a neighborhood

their role within city areas (collector streets, local street providing

accessibility to buildings)

A. Ancient, dense and valuable urban tissue

B. Monofunctional low density residential area with single-family dwelling

C. Residential area with high collective dwellings and with low land

occupancy percentage

D. Secondary activities / industrial area etc.

Areas with high / very high exigencies for quality of public spaces and

road safety

Street landscape character – in different street sequences according to the

traversed city area

Places for changing the urban character of streets sequences (roundabout,

intermodal transfer hubs)

A

B C D



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functional and morphologic characteristics of the areas their are passing

through

level of exigencies for protecting living environment quality and/or urban

heritage of different city areas.

The ratio between “infrastructure for traffic” function and “living space”

function is thus different, by category of streets:

1. streets with prevalent function of “traffic artery” - arteries- arterial and

sub-arterial roads (categories 1, 2) 2. streets with an equilibrate ratio between the function of “infrastructure

for traffic” and the function of “living space”– collector streets, on which

public transport can pass inside the neighborhoods,

3. streets with prevalent function of “living space”– local streets directly

providing accessibility to buildings (see. fig.5, fig.6)

Figure 5. Classification of streets according to their ratio between

“infrastructure for traffic”/arterial function and “living space” function Source; the author

In conclusion, within neighborhoods it is needed and now reaffirmed streets

quality of living space on which largely depends the urban well-being of

communities. The improvement of public space ambience, travel comfort and

safety relies on a new approach of organizing streets and traffic: Redistribution and remodeling of street space: the increase of share for

environmentally friendly travels infrastructure - sidewalks, bike lanes and

max.800

m max.800

m

Collector

streets

Local streets

Streets with

dominance of

“living space”

function

Streets with

dominance of

“traffic

infrastructure”

function

Arterial

roads

Sub-arterial

roads



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bike-parkings- creation of pedestrian streets, squares and/or areas, facilities

for rising travels safety, landscaping.

Decrease of travel speed on streets with dominant function of "living

space": 50 km/h on collectors with public transportation, 30-20 km/h on

local streets.

Such measures tend to generalize within neighborhoods in major European

cities, which turns it into "zones '30”, “controlled traffic zone", "low emissions

areas" etc.. In the context of the speed limit to 20 km/h, even 10 km / h, a new

model of street and squares is also experienced in many European cities: the

"shared space" – public space in common shared by pedestrians, cyclists and

cars, whose organization is based on the responsibility of all its users and

especially of motorists, without physical delimitation of roads and with reduced

signage, thus having important landscape benefits and improved travels safety

and ambience. (see fig.7)

Figura 6. Differentiation of streets urban character according to their ratio

between their function of road and their function of living space: a. arterial or

sub-arterial (preferably treated as avenues), b. collector roads c. local streets /

pedestrian / shared space.

4. CONCLUSIONS

Defining the new sustainable mobility paradigm, promoted at the European level

by specific key documents1, announces the decline of the old paradigm of

unconditional and undifferentiated adaptation of cities to motorized traffic,

proposing the reshape of urban travels systems aiming at the reharmonisation of

accessibility needs with the exigencies for quality of public spaces, protection of

urban heritage, improvement of ambience and safety of the living environment.

1 Action Plan on Urban Mobility, Commission of The European Communities, Bruxelles, 30.9.2009;

Green paper-Towards a new culture for urban mobility, Commission of The European Communities, Brussels,

25.9.2007

a b c



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Automobility must be managed, controlled and limited within cities and their

metropolitan areas, especially in the city areas where motorized traffic has

caused major dysfunctions. Some of the methods outlined in the European

practice are based on detour road systems (peri-and inner-city), intermodal hubs

as primary tool for modal restructuring mobility, reformulation of urban

character of streets not only according to their functional role, but also according

to the exigencies of the areas they are located in, totally or with trail sequences.

Figure 7. Shared space – low speed traffic urban environment

Source of the foto:”Nouvelle energie pour Septeuil”,

http://www.voleospeed.co.uk/2011/07/byng-place-and-influence-of-anti.html

BIBLIOGRAPHY [1]. “SAFENET- Research to estimate and increase the intrinsic safety performances of

urban traffic networks” – Scientific report phase1, PNCDI, PCCA TIP 2 project,

Ministry of Education and Research, 2012

[2]

[3]

[4]

[5]

NEGULESCU, Mihaela Hermina, “Mobility and urban form – theoretical issues”,

“Ion Mincu” Academic Publishing House, Bucharest, 2011

*** Action Plan on Urban Mobility, Commission of The European Communities,

Bruxelles, 30.9.2009 şi

*** Green paper-Towards a new culture for urban mobility, Commission of The

European Communities, Brussels, 25.9.2007

*** “Nouvelle energie pour Septeuil”, http://www.voleospeed.co.uk/2011/07/byng-

place-and-influence-of-anti.html

FORMULAS OF TRAFFIC AND STREETS (RE)SHAPING, FOR A NEW QUALITY OF LIVING AND TRAVELS SAFETY IN...

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