Select Committee on Transport, Local Government and the Regions Appendices to the Minutes of Evidence


Memorandum by Whitby Bird & Partners (RTS 40)

ROAD TRAFFIC SPEED INQUIRY

1.  BACKGROUND

  Reducing the problems caused by inappropriate speed of vehicles in towns and on rural roads is central to the transport policies of most countries in mainland Europe. Given the high casualty rate for pedestrians and cyclists in towns in the UK, an understanding of recent policy initiatives and highway design principles from other European countries may be helpful to the Committee. This submission touches upon a number of fundamental principles relating to road design, traffic calming, road classification and physical measures such as road markings and barriers. It recommends that changes are made to the guidance given by government to local highway authorities on the underlying design philosophy for secondary and minor roads in cities, towns and villages.

2.  INFLUENCING DRIVER BEHAVIOUR

  Research carried out at the Institute for Traffic Psychology at Groningen in The Netherlands and supported by experiments elsewhere in Denmark, Germany and Sweden indicate that the environmental context is the most important influence on drivers' behaviour. The design of the road, the degree of isolation from the surroundings and the perceived absence of hazards and conflict points are the key determinants of speed. Signs and other legal or advisory restraints have little effect on speed reduction. In countries where 30 kph (18 mph) is becoming accepted as the maximum for urban areas, policies are being developed to reduce speeds through

    —  Reducing the traffic engineering element in road design.

    —  Ensuring that roads are integrated with, and not isolated from, their surrounding built and natural environment.

    —  Reducing confidence levels of drivers by introducing uncertainty and ambiguity, encouraging driver—pedestrian interaction, and removing perceptions of priorities.

3.  SEGREGATION VERSUS INTEGRATION

  For many years, the emphasis in highway engineering has been placed on design measures to separate vehicles from pedestrians. This was one conclusion emerging from the "Traffic in Towns" report prepared under the chairmanship of Sir Colin Buchanan in 1961, and the familiar street furniture of kerbs, barriers, road markings, traffic islands and pedestrian crossings all underpin such segregation. Only recently has the UK government begun to introduce the concept of "Home Zones" following their widespread adoption in residential areas across mainland Europe. Home Zones represent a fundamental challenge to the principle of segregation, encouraging the integration of vehicles with a wide range of social activities through the use of shared space. Meanwhile Dutch and Danish planners and traffic engineers are rolling out such principles into the broader urban context, and achieving significant reductions in vehicle speeds and pedestrian casualties as a result. This paper argues that the DTLR should look carefully at the outcome of such developments, and use their findings to question the principle of segregation of traffic and pedestrians in towns.

4.  TRAFFIC SPACE AND SOCIAL SPACE

  A key principle to changing the behaviour of drivers and improving safety for pedestrians involves a clear distinction between two types of road. On one side, motorways, major dual carriageways and trunk roads represent the "traffic zone", designed solely for the efficient movement of vehicles between places. Such roads serve a single purpose, and are deliberately isolated from their surroundings. Other activities and vulnerable road users are segregated. At the other end of the spectrum, most urban roads (and many minor rural roads) serve a multitude of functions, of which the movement of vehicles is only one. The residential mews or cul-de-sac is the extreme example, but most High Streets serve a wide range of social purposes in addition to traffic movement and parking.

  The Dutch government's "Sustainable Safety" initiative draws a clear distinction between these two components of the highway network, and requires highway authorities to treat them very differently. The distinction implies the need for very clear "gateways" to be established at the transition points, so that entry into the social space of an urban area is clearly defined. Within such gateways, all the conventional language of the traffic zone (kerbs, road markings, priority signals etc) is removed. Instead, emphasis is given to the use of eye contact as the principal means with which to negotiate movement.

5.  TRAFFIC CALMING OR LEGIBLE ROADS?

  The distinction between social roads and traffic roads as a means to reduce speeds has important implications for the design of streets and the use of traffic calming. Whereas local authorities in the UK have come to rely on measures such as road humps, chicanes and similar devices to reduce traffic speeds, many Dutch, Danish and Swedish planners and engineers are increasingly adopting measures which emphasise the social context of the road in order to change behaviour. Thus, for example, a street passing a school, a church or a shop will reflect the presence of such institutions and their role through the alignment, the use of materials and the absence of barriers. Every desire line, every small footpath or characteristic of a place can be employed to emphasise the social context and counteract the tendency for streets to become traffic corridors. In the province of Friesland in the north of The Netherlands, road markings are no longer used in built-up areas. Traffic movement and speeds are determined solely through the need for negotiation and eye contact. Intersections have no priorities, and there are few defined pedestrian crossing points. Counter-intuitively, the results suggest that traffic flows can improve. Pedestrian and bicycle casualty rates would appear to reduce significantly through such an approach.

6.  POLICY IMPLICATIONS

  This paper recommends that the Committee takes careful note of the approaches to speed control and safety being adopted in mainland Europe, particularly in Denmark, Germany, Sweden and The Netherlands. It argues that the safety of pedestrians and other road users can only be achieved through significant reduction of speeds in urban areas and on minor roads. Such reductions can be most effectively achieved through sending clear and consistent messages concerning the distinction between transit roads and streets that provide for multiple uses. To achieve such changes, the Committee is urged to adopt a consistent approach to the design of urban and minor rural roads, based on:

    —  The adoption of 20 mph as the maximum design speed (equivalent to the 30 kph being introduced in mainland Europe).

    —  The introduction of clear gateways at transition points between major roads and urban areas.

    —  Extending the principles embodied in "Home Zones" to the wider urban context.

    —  The removal of traffic measures designed to facilitate speed on such roads, such as centre line markings, priority junctions and long sight lines.

    —  The redesign of existing "yellow line" parking restrictions, which emphasise the linear nature of streets and divorce the carriageway from the surrounding environment.

    —  The removal of elements that separate the pedestrian zone from the carriageway. Conventional kerbs, barriers and light-controlled crossings should be discouraged. Local Transport Notes 1/95 and 2/95 should be withdrawn, and new advice drafted.

    —  A revision of driver training and the Highway Code to reflect the importance of negotiation and eye contact as a means to negotiate movement in urban areas.

7.  RECOMMENDATIONS

  Many of the principles described above can be best described through graphics and photographs. The Committee is invited to arrange for a presentation of examples of recent initiatives in this field from mainland Europe. The Committee is also recommended to make contact with equivalent policy making bodies in a number of European countries, and to arrange study visits as appropriate. The author would be pleased to help provide relevant contacts and recommendations.

Ben Hamilton-Baillie

Director for Sustainable Transport & Urban Design

4 January 2002



 
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