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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