Killing Speed: a good Practice Guide to Speed Management

Starston is a village in Norfolk which had identified speed management as part of an overall scheme to improve non-car access to the nearby town, particularly for journeys to school. Residents were therefore campaigning for a 30mph speed limit through the village.
However, the Council considered the road through the village was too short to get the desired response: "The road environment wasn’t going to convey the right messages for that ‘urban’ speed limit." The introduction of a 30mph limit would have required 26 signs, leading to clutter.
Instead, a scheme was devised to achieve speed reduction without a new speed limit. Natural traffic calming features, such as a right-angled bend approaching a bridge, were augmented. Signing and markings were reduced: 11 warning signs were removed, including one motorway standard chevron (another chevron was kept). The centre white line was removed, except at the bend. The road surface was dressed in an attractive brown stone chosen by local people, who also commissioned a village gateway sign from a local artist. The measures achieved the desired results, as speeds through the village were indeed reduced to around 30mph.
Contact:
Norfolk County Council

Planning and Transportation

County Hall

Norwich NR1 2SG

(tel: [phone])
4.5 Poundbury, Dorset : designing new urban spaces with a human scale
Many new towns have been designed around the car, and many existing communities have been overwhelmed by the car. In recent housing schemes, roads have taken their form from the requirements to achieve movement of motor traffic. Buildings have been arranged around the car, which has inevitably led to an unnatural and inhuman environment.
At Poundbury, a new-build development which is part of the Duchy of Cornwall, a different approach has been taken. To begin with, designers have focused on creating pleasing urban spaces. Buildings have then been placed around the spaces so as to produce an overall design with a human scale.
Pavements and roads have then been fitted informally into the urban spaces so that movement of vehicles and pedestrians is safe and easy. In some places roads have greater width, providing on-street car parking. Pavement widths also vary and are particularly generous at road junctions, in order to maximise visibility for drivers.
The layout provides effective speed control without the need for additional constraints. Junctions generally reduce vehicle speeds considerably. More frequent junctions mean slower movement throughout Poundbury. Vehicle speeds are also contained by changes of surface at the entrance to squares where pedestrians have priority. Vehicles have full access, but priority is given to the creation of coherent, attractive neighbourhoods. The network of spaces at Poundbury gives a clear identity to each part of the development.
Section 17 of the Crime and Disorder Act 1998 imposes a duty on local planning authorities to exercise their function with due regard to preventing crime and disorder. There is considerable scope to meet the road safety elements of this requirement at no extra cost by designing low speeds into new-build developments from the earliest design stage, exactly as has been achieved at Poundbury.
Contact:
Ian Madgwick

Environmental Services Department

Dorset County Council

Dorchester

Dorset DT1 1XJ

(tel: [phone])

4.6 References for Section 4
Department of Transport (1997) Traffic Advisory Leaflet 2/97: Traffic Calming on Major Roads – A49, Craven Arms, Shropshire, London: DoT
Derbyshire County Council (2000) Highway signs: Environmental code of Practice, Matlock: DCC
Department of the Environment/Department of Transport (1992) Design Bulletin 32, Residential roads and footpaths – Layout considerations (2nd edition), London: Stationery Office
DETR (1998) Places, Streets and Movement: A Companion Guide to Design Bulletin 32 (Residential Roads and Footpaths), London: DETR
DETR (2000) Traffic Advisory Leaflet 1/00: Traffic Calming on Major Roads, London: DETR
English Heritage (2000) Streets for All: A guide to the management of London’s streets, London: English Heritage
Farmer, S, Barker, J and Mayhew, N (1998) ‘A trial in Norfolk of interactive speed limit signs’, Traffic Engineering and Control, May, pp287-292
Traffic Engineering and Control (2000) ‘Fibre optic signs show excellent driver response’, pp81-82
West Lothian Council (1998) Strategic Services Committee, 17 November 1998, Traffic Calming Measures
SECTION 5
INTRODUCING LOWER SPEEDS LIMITS
5.1 Suffolk County Council village speed limit initiative
In 1994 Suffolk County Council set up a Speed Management Panel of council members to consider a speed management strategy for the County. The question addressed by the Panel was: ‘What can the County Council do to bring about a change in attitudes about speed?’ The Panel agreed that the needs and expectations of the local community were of paramount importance, rather than those of passing motorists (Suffolk County Council, 1997).
The County Council introduced its village speed limit initiative between November 1994 and December 1996. The Council rejected the advice of the Department of Transport’s Circular 1/93 on existing driver speed and set out with the presumption that each village or location where groups of people live should have a 30mph speed limit. The policy was to introduce a consistent speed limit for all residential areas, even tiny hamlets. The Council hoped that the implementation of the policy would lead to an improvement in safety and the quality of life of residents in the county.
By December 1996 an estimated 700km of 30mph limit had been introduced in Suffolk – probably the largest recent implementation of new speed limits by any local authority in the UK. Over 450 new 30mph speed limits were installed within the two-year period, at a cost of approximately £4,500 per speed limit. A total of 280 new speed restrictions were established, and 85 parishes introduced significant extensions to already existing 30mph limits. A further 85 parishes had speed limits reduced from 40 to 30mph. The overall cost was £1.2 million, averaging £2,500 per village. The initial estimate for the work had been £2 million, but economies of scale and geographic grouping of the work programme managed to reduce the total by 40% (Jeanes, 1997).
There was poor awareness of the local speed limit before the installation of the new signs, but almost total awareness after implementation, according to a survey of village residents carried out by the Transport Research Laboratory (TRL, 1996a). The extent of the speed limits was agreed with local people, overseen (and sometimes arbitrated) by the Speed Management Panel. The TRL survey found that 66% of village residents were enthusiastic about the policy, although a further quarter disapproved. Three quarters of all respondents had noticed changes to the speed limit in Suffolk villages other than their own.
The major area of concern was danger to pedestrians and cyclists, especially child pedestrians, with at least a third of respondents strongly agreeing that traffic was dangerous to these groups both before and after the new speed limits were introduced. A fifth of respondents also believed their quality of life had improved with the implementation of the new signs, although 77% felt it remained the same as before.
Speed reductions within the new speed limit areas were found to have resulted in 20% fewer crashes compared to Suffolk roads on which there had been no change of limit. Comparisons were also made between unrestricted roads in Suffolk and Cambridgeshire, and it was found that there were proportionately fewer crashes in Suffolk. The County Council has concluded, therefore, that the 30mph restrictions did not lead to an increase in crashes on adjacent unrestricted roads.
The reduction in the number of crashes was estimated at 130 across all the speed limit areas in the period since implementation of the new limits. This equates to a reduction of 45 crashes per year across the speed limit areas. It was found that reductions in crashes were greater where the speed limit was reduced from the national speed limit of 60 to 30mph than where the change was from 40 to 30mph. Where speed limits were reduced from 60 to 30mph there was an average speed reduction of 6.2mph, while where speed limits were reduced from 40 to 30mph there was an average speed reduction of 4mph. Suffolk County Council’s county-wide approach was acknowledged in the government’s Review of Speed Policy for its success in reducing casualties.
Contact:Mike Jeanes

Environment and Transport Department

Suffolk County Council

St Edmund House

County Hall

Ipswich IP4 1LZ

(tel: [phone])

5.2 Oxfordshire County Council 30mph limits

In August 1997 Oxfordshire County Council resolved to introduce 30mph limits in most Oxfordshire settlements, subject to agreement with parish and town councils. A settlement was defined as a continuous built-up area of at least 20 houses, but schools and businesses generating greater vehicular or pedestrian flows than an average house can compensate for fewer dwellings.
Starting in the Vale of the White Horse and West Oxfordshire, the County Council has acknowledged the work undertaken by Suffolk County Council in its resolve to implement 30mph speed limits across the county. It has also planned to monitor sites in order to provide ‘before’ and ‘after’ data.
Contact:
Geoff Barrell

Environmental Services

Oxfordshire County Council

Speedwell House

Speedwell Street

Oxford OX1 1NE

(tel: [phone])

5.3 20mph zones

The first three 20mph zones in the UK were implemented in January 1991. Five years later the Transport Research Laboratory reviewed the results from 250 zones in England, Wales and Scotland (TRL, 1996b), with the following major findings:
average speeds had fallen by 9mph

the annual total of crashes had fallen by 60%

the number of crashes involving children had fallen by 67%

crashes involving cyclists had fallen by 29%

Traffic flows in the zones had been reduced by 27%, but flows on the surrounding boundary roads had increased by 12%. There had been little crash migration to surrounding roads.

There are now around 500 such zones across the UK. Since June 1999 local authorities in England (Circular 05/99), Wales (Circular 28/99) and Scotland (Circular 13/99) no longer need consent from the Secretary of State before implementing 20mph speed limits. There are two different means of implementing 20mph speed limits: (a) where speed limits are indicated by entrance and repeater signs alone; (b) where a combination of signs and traffic calming measures provide self-enforcement. The vast majority of schemes consist of self-enforcing traffic calming schemes, partly because the police cannot guarantee sufficient resources to enforce ‘signs only’ 20mph limits.

5.4 Scottish trial programme of advisory 20mph speed limits
Indications to date suggest that schemes with fewer physical measures have a lesser impact on speed than schemes with more physical restrictions, both in urban and rural locations (DETR, 1999; Silcock, 2000). In Scotland, however, the Society of Chief Officers of Transportation in Scotland (SCOTS) invited councils to participate in a trial of advisory 20mph speed limits, using 20mph signs and markings in areas where the official speed limit remains 30mph. The 18-month trial began in spring 1998, and involved 75 sites from 27 councils. The Scottish Office (now Scottish Executive) commissioned consultants to carry out research into the impact of the advisory speed limits, including attitudinal surveys among residents.
Results show that even these ‘signs only’ measures have been successful in bringing or keeping average speeds under 20mph. The advisory 20mph limits have been particularly effective where the ‘before’ speeds were in the upper range of the sample. Interim results from a sample of speed surveys (see Table 5) show that at seven survey sites there were decreases in average speed, one site recorded an increase, and five sites experienced no change. Final results seem to bear out the interim findings, and to confirm that local residents are pleased with the overall drop in speeds.
Table 5: Average speed and severity factor changes in Scottish advisory 20mph limits trial (interim results)

average speed severity factor

location before after change before after change

Lochside/Denmore Park, Aberdeen 29 17 -12 0.466 0.121 -0.345

Broomfield Road, Portlethen 21 17 -4 0.200 0.128 -0.072

Wallamhill Road, Dumfries & Galloway 16 16 0 0.076 0.081 +0.005

Buckstone Crescent, Edinburgh 26 25 -1 0.354 0.326 -0.018

Buckstone Loan, Edinburgh 26 26 0 0.360 0.338 -0.022

Buckstone Loan East, Edinburgh 22 20 -2 0.232 0.182 -0.050

Oliver Road, Falkirk 23 21 -2 0.267 0.191 -0.076

Moncks Road, Falkirk 21 20 -1 0.200 0.177 -0.023

Hawley Road, Falkirk 18 20 +2 0.147 0.204 +0.057

Cromwell Road, Falkirk 22 21 -1 0.241 0.219 -0.022

Marchburn Drive, Midlothian 19 19 0 0.156 0.152 -0.004

Milton Quadrant, Kilbirnie 24 24 0 0.285 0.265 -0.020

Stockbridge Cresc, Kilbirnie 21 21 0 0.212 0.185 -0.027

Table 5 also provides a calculation of the severity factor, calculated from the likely degree of severity of injury to a pedestrian struck by a motor vehicle at various speeds. This is intended to allow a comparison between sites and the effectiveness of the measures. As a benchmark, if all vehicles travelled at 20mph then the severity factor would be 0.100.
Contact:
Janet Ruiz

Central Research Unit

Scottish Executive

Victoria Quay

Edinburgh EH6 6QQ

(tel: [phone])

5.5 Kingston Upon Hull: 20mph zones programme
In the mid-1990s Hull City Council launched a programme of implementing 20mph speed limit zones, and by summer 2000 a total of 80 zones had been established. One reason for their widespread introduction was that the city has casualty rates for child pedestrians and cyclists well above the national average. It also has a relatively high level of cycle use, with a modal share of 14% for the journey to work. In addition, 51% of households in Hull have no car, which is also well above the national average.
Typical speed reductions in 20mph zones vary according to the types of measures applied. Schemes using road humps only have been most effective, bringing down mean speeds to 17mph. Speed cushions together with road narrowing have brought speeds down to 20mph, while schemes using cushions only have brought speeds down to 22mph.
As the result of concerns expressed by the Ambulance Service, the City Council has agreed that from 1999:
all vertical measures will be a maximum 75mm high

all cushions will be 2.1m wide with 550mm side slopes

all speed table ramps will be 1800mm long

all schemes will include the minimum number of measures to achieve objectives

bollards will be placed adjacent to humps/ cushions as markers on local distributor roads

the Council will revisit earlier schemes to make them ambulance-friendly

Since the introduction of the Crime and Disorder Act 1998, all local schemes have also been subject to a police crime and disorder audit. Public consultation has been conducted by leaflet and questionnaire to all households on all schemes, together with public exhibitions and occasional feedback sessions to update residents on progress, as well as presentations to ward forums and residents associations.

Questionnaires have typically met with response rates of around 25-40%, of which:

80-90% are in favour of 20mph zones

70-80% are in favour of humps/cushions

60% are in favour of narrowings/priority workings

Three schemes to date have not received a majority mandate and so have not progressed. By summer 2000 there were over 70 sites with petitions for traffic calming, as well as three requests for home zones (one from an existing 20mph zone). The Council now considers home zones as possible parts of all future traffic calming and 20mph zones.

The results of Kingston Upon Hull’s 20mph zone programme have been impressive, particularly in 13 zones installed in 1996/97. The total number of crashes within these zones has fallen by 56%, while the number of people killed and seriously injured has fallen by 90%. The Council also saw a first year economic rate of return from these schemes of 1,160%.
Contact:

Tony Kirby

Road Safety Unit, Traffic Services

Kingston Upon Hull City Council

Kingston House

Hull HU1 3ER

(tel: [phone])
5.6 City of Edinburgh Council: 20mph zones
Since August 1998 City of Edinburgh Council has primarily focused on converting existing traffic calming schemes to self-enforcing 20mph speed limits. The first tranche of traffic calming schemes approved for conversion required additional measures costing between £4,000 to £75,000 per scheme, depending on the extent of the work required (City of Edinburgh, 2000):
Broomhouse £20,000

Calders £15,000

Devon Place £6,000

Duddingston Village £4,000

Dundee Street £6,000

Grange £24,000

Royston/Wardieburn £75,000
The Council has also consulted widely with interest groups in the different residential districts affected by proposals to change traffic calming schemes into 20mph zones. In South East Edinburgh, for example, 104 groups were consulted. Out of the 20 responses, only Lothian Regional Transport objected to the proposals, whilst other groups sought extensions of the pilot area (City of Edinburgh, 1999).
The provision of 20mph speed limits outside primary schools was agreed by the Council in 1998 and is being taken forward as part of the Safer Routes to Schools programme. Due to cost implications, the progress of the programme will be dependent on future capital budget allocations (City of Edinburgh, 1999). The budget for implementation of 20mph zones in Edinburgh is £510,000 between 2000 and 2003.
By March 2003 roughly 10% of the city’s road network in built-up areas will be covered by 20mph zones.
Contact:
Phil Noble

City Development Department

City of Edinburgh Council

1 Cockburn Street

Edinburgh EH1 1BL

(tel: [phone])

5.7 Buxtehude, Germany:speed reduction through area-wide Tempo 30
Buxtehude is a town of 32,000 inhabitants in the north of Germany, 34km south-west of Hamburg. It was one of six locations selected to take part in the national traffic calming demonstration project of the former West Germany. In this context Buxtehude developed one of the most comprehensive examples of area-wide traffic calming and Tempo 30 zones, and became one of the models for the Tempo 30 programme extended across Germany during the 1990s.
Specifically, 30kph limits have been established in the centre and northern districts of the town, where around 11,000 inhabitants live. The Council has used an extensive public relations programme to explain the plans in order to win support from residents.
The measures have been implemented in two main phases. During 1983 two main Tempo 30 areas were established, with narrowing of entrances to the areas. The second stage began in 1986 and was completed in 1987. It included the renewal and part conversion of distributor roads, conversion of a main street into a ‘shopping boulevard’, and conversion of some streets into pedestrian zones in the oldest part of Buxtehude.
A five-tier road hierarchy is used in Buxtehude, as in many other areas of Germany, to provide a guide to the types of measures appropriate in different parts of the network. This comprises:

pedestrian zones (Fussgängerzonen), usually shopping areas, where motor traffic is removed

residential streets (Wohnstrassen), where traffic calming is often widely applied and where all through traffic is removed

collector roads (Sammelstrassen), where speed reduction is achieved by reducing space for motor vehicles

main roads (Hauptstrassen), where there are possibilities for speed reduction measures, tempered by the needs of through traffic, public transport and service vehicles

limited access roads (Autobahnen), which have speed limits in urban areas only

The results of Tempo 30 in Buxtehude have been impressive: the number of casualties in the 30kph areas dropped by 60%. Nor has the introduction of lower speed limits been confined to residential streets. Traffic calming measures and carriageway width reductions on main roads have also helped to reduce both traffic casualties and speeds.

On residential roads 85th percentile speeds fell from 44 to 35kph on average, and on main roads from 53 to 40kph. On the surrounding roads where there is no 30kph speed limit, speeds have fallen from 54 to 51kph (see Table 6). These changes led to increases in pedestrian and cycle traffic in the area of 17% and 27% respectively. Over the same period car traffic increased by only 2%.

Table 6: Mean and 85th percentile speeds in Buxtehude before and after Tempo 30 (all speeds in kph)

before (1983) after (1988)

mean 85th %ile mean 85th %ile

Residential roads 35 44 32 35

Distributor roads 45 53 34 40

Surrounding traffic roads 54 64 51 60

The conversion of one of the main streets in the centre of Buxtehude, Bahnhofstrasse, into a ‘shopping boulevard’ was achieved by narrowing the road to 6.5 metres and raising all junctions. Cycle paths were built in both directions. The mean speed declined from 42 to 33kph, while the 85th percentile speed fell from 48 to 41kph.

5.8 References for Section 5

City of Edinburgh (1999) City Development, Transportation Committee, 20mph speed limits: statutory changes, 9 August 1999
City of Edinburgh (2000) City Development, Transportation Committee, 20mph speed limit zones in existing traffic calmed areas, 10 April 2000
Danish Road Directorate (1993) An improved traffic environment: A catalogue of ideas, Denmark: Herlev
DETR (1999) Traffic Advisory Leaflet 9/99: 20mph Speed Limits and Zones, London: DETR
Jeanes, M (1997) ‘Suffolk’s 30mph speed limit initiative’, (edited and updated version of 1996 PTRC paper), Suffolk County Council
Oxfordshire County Council (1999) Oxfordshire County Council’s 30mph speeds limit project – West Oxfordshire, Oxford: OCC
Scottish Executive (1999) Evaluation of the 20mph speed reduction initiative: Interim report (unpublished)
Silcock, R (2000) ‘Design issues for rural traffic management’, in Design issues for rural traffic management: Conference Proceedings, by Landscape Design Associates and Ross Silcock Limited, Cheltenham: Countryside Agency
Suffolk County Council (1997) 30mph speed limit initiative: Speed monitoring, Ipswich: SCC
Transport 2000 (undated) A set of case study examples of good practice from German speaking countries, unpublished report by Julia Rohrig
Transport Research Laboratory (1996a) Suffolk 30mph speed initiative independent survey, by Farmer, S, unpublished Project Report PR/TT/129/96
Transport Research Laboratory (1996b) A review of traffic calming schemes in 20mph zones, Report 215, by Webster, D and Mackie, A, Crowthorne: TRL
SECTION 6
ENFORCEMENT, EDUCATION AND TRAINING
6.1 Speed cameras
Section 23 of the Road Traffic Act 1991, which came into force on 1 July 1992, provides that in the prosecution of drivers for exceeding speed limits photographs from an approved automatic speed camera may be used as evidence without the corroboration of a police officer. Funding for start-up purchasing costs of speed cameras is usually shared between local authorities and the police, although it can also include the Highways Agency and Crown Prosecution Service and the courts (DETR, 1999).