Today I met a representative of the local authority at my home to discuss my proposal for a 20mph speed limit zone in my area. It was a good meeting. He was quite sympathetic to the project having been once involved in implementing such schemes in Northampton. Some ideas were new to me.

One of the big problems is that often the majority of residents in a zone will be quite enthusiastic about a scheme but friction can arise when speeds do not drop after its introduction and people feel let down.

Another factor that is new to me is that once a 20mph zone is in place then the police stop monitoring the speed in the area, they consider that the local authority have taken it upon themselves to manage the speed in the area.

He thought that one way to make progress was to try to combine the scheme with a proposal for a community action group. He will find out about these and contact me again.

Notes on problems encountered when implementing 20mph zones in towns.

These notes summarise the nub of the case that I am trying to make.

Introduction
The background
The problem examined.
Recommendations.
Appendices.

1. Introduction
The Department for Transport (DfT) has encouraged the implementation of measures to improve safety on the UK road network. These Notes suggests that the guidelines that have been introduced under its auspices are not being followed which is leading to the unnecessary perpetuation of dangerous and unsatisfactory environments

2. Background
The DfT in its reports:--
“Update of Circular 1/93, Setting local speed limits”, [SLSL]
“New directions in speed management: a review of policy” [NDISM] has:--

*Encouraged local authorities to give more weight to the safety and environmental needs of the people living in residential areas when measured against the needs of traffic attempting to gain access to these areas. See Appendix 1
*Highlighted the very significant increase in the incidence of serious injury and death in collisions involving a pedestrian when the vehicle speed is 30 or 40mph as against 20mph. Appendix 2
*Reported research which shows that the introduction of a speed limit without at the same time constraining vehicle speed with traffic calming measures will reduce the average speed of vehicles by only two or three miles per hour. Appendix 3
*Stipulated in a bold move that speed limits should be set on the basis of actual average speed of traffic in any given situation rather that the 85th percentile speed as was previously the case. This should significantly ease the introduction of lower speed limits. Appendix 4
*Made it a requirement that zones should be ‘self-enforcing’, ie after the implementation of a zone the average speed should be at or below the new limit. Appendix 5

3. The problem examined.
In spite of the encouragement of the DfT several factors seem to be conspiring against the use of 20mph zones.
A mindset among the local authority traffic departments that equates 20mph zones with traffic calming measures. As there is a widespread public hostility towards road humps, if zones come with road humps then zones are not wanted. But as stated in paragraph 80 cited in Appendix 3 zones are permissible without traffic calming measures provided the speed is at or below 24mph.
A Catch 22 situation arises where if it can be shown that the average speed in an area is already 20mph then how can the cost of the introduction of a 20mph zone be justified? Implicit in this opinion is probably an unconscious and unwarranted assumption that expensive civil engineering works will be necessary.
There are political pressures at work through the British tradition which attaches great importance to the freedom of the individual. Constraints on speed are often painted by certain sections of the media as an infringement of these liberties. There is also the concern of elected members that the public should not be ‘nannied’.
Because the quality of the living space in a residential area, and its use as a meeting place is impossible to value in monetary terms then this aspect of the a prospective 20mph zone is not given sufficient weight.
The official guidance is comprehensive and detailed and must be dealt with as a whole. However it seems that negative aspects of the circulars are often extracted and presented out of context. For example NDISM, page 19 par 122 says “.Where speeds of 20 mph are necessary, self-enforcing 20 mph zones have proved very successful. All research to date into the relationship between speed limits and vehicle speeds points to 20 mph limits being relatively ineffective without traffic calming”. But it is not the case that traffic calming measures are necessary where the average speed is already low. And I would contend that most residential areas in towns already have a low average speed so are the ‘norm’.
SLSL on page 10, par 27 compares Benefits and Disbenefits in setting local speed limits. The list of Benefits is uncontroversial but the Disbenefits seem to be ‘padded out’ to give an appearance of an even handed approach. For instance one Disbenefit is deemed to be ‘Increased journey times for motorised traffic’. This seems unlikely [to be kind about it] given that if one considers a typical journey where a vehicle moves within its residential area onto an arterial road, travels along the artery until it perhaps enters another residential area. The proportion of the journey within the residential area will be a minor part and any time that would be saved by travelling at 30 rather than 20 is minimal.

4 Recommendations
Although the draft re-write of Circular 1/93 Setting local speed limits has stated the case for 20mph zones the complexity of the guidelines has led to them being misinterpreted. The final publication should eliminate any ambiguity.
If the publication of the final edition is delayed then an interim statement should be made for the sake of clarity.
There should be a requirement that if a residential area already has an average speed on its roads of less than 24mph then the local authority should introduce a 20mph zone unless there are special circumstances which would preclude such a zone.
The use of the phrase ‘vulnerable road users’ should be reconsidered given that all pedestrians bleed when struck by fast moving vehicles.

Appendix 1.
Page 7 of the Government’s response regarding road traffic speed, CM5621, 2001

“The policy climate has now changed with more encouragement being given to providing greater priority and convenience to pedestrians and other vulnerable road users. Key elements in achieving this are:
• reducing vehicle speeds;
• making better and safer provision for pedestrians;
• promoting sustainable transport alternatives;
• improving the general street environment”.

Page 19 of NDISM says in par 123:--
“Within town centres and other areas with a mixture of land uses, planning guidance already recommends that priority should be given to people over traffic”. [emphasis added]

Appendix 2
From page 9 of New directions in speed management: a review of policy
“Speed and injury severity
42. For pedestrians and cyclists the reality is even more stark. At-the-scene investigations of collisions involving pedestrians and cars or car-derived vans found that 85% of fatalities occurred at impact speeds below 70mph. This compared with 45% which occurred at less than 30mph and 5% at speeds below 20mph. [emphasis added]

Appendix 3
Page 17 of Update of Circular 1/93 Setting local speed limits
“80. Research into 20mph speed limits carried out by TRL (TRL Report 363) showed that where speed limits alone were introduced, reductions of only about 2mph in mean speeds were achieved. 20mph speed limits are therefore only suitable in areas where vehicle speeds are already low (the Department would suggest where mean vehicle speeds are 24mph or below), or where additional traffic calming measures are planned as part of the strategy.” [emphasis added]

Appendix 4
Page 12 op. cit.
“37. Circular 1/93 advised the use of 85th percentile speed to determine local speed limits. This refers to the speed at, or below, which 85 per cent of the traffic is travelling. Viewed another way it is the speed only 15 percent of drivers exceed. Practitioners' thinking has evolved since then and many have expressed concern that 85th percentile speed can be heavily influenced by excessive speeds travelled by a minority of drivers. Some Traffic Authorities have therefore adopted the use of Mean speeds in assessing what is an appropriate local speed limit, as they are felt to better reflect what the majority of drivers perceive as an appropriate speed for the road. The Department shares this view and therefore recommends that mean speeds be used in future assessments of appropriate speed limits”. [emphasis added]

Appendix 5
Page 14 op. cit.
74. Successful 20mph zones and 20mph speed limits should be generally self enforcing. Traffic Authorities should take account of the level of police enforcement required before installing either a 20mph zone or 20mph speed limit. 20mph speed limits are unlikely to be complied with on roads where vehicle speeds are substantially higher than this and, unless accompanied by the introduction of traffic calming measures, police forces may find it difficult to routinely enforce the 20mph limit. Traffic Authorities should therefore always consult the police when considering possible 20mph limits or zones, and thereafter as part of the formal consultation process. [emphasis added]

Appendix 6
Page 11 paragraph 32
….Introducing or changing a local speed limit indicated by signing alone without accompanying education and effective engineering changes to the road itself is unlikely to have sufficient influence on driver behaviour to change actual speeds to below the new limit.