Agenda item

13/00063 - 20mph Speed Limit Policy - Review


(1)       Further to Minute 27 of 4 July 2012, the report presented national and local evidence on the benefits of 20mph schemes and recommended a new policy that the County would seek to implement 20mph schemes when there were clear road safety or public health benefits.  Any locally supported schemes that could not be justified in those terms could still be implemented via the Member Highway Fund provided they were implemented as set out in Department for Transport Circular 01/2013.


(2)       The policy would feed into the new Road Casualty Reduction Strategy which was being developed by Highways & Transportation to assist with meeting targets set out in Bold Steps for Kent and delivering the priorities set out in Growth Without Gridlock (GWG).


(3)       In recent years the demand for the implementation of 20mph schemes had been increasing in response to both local and national campaigns.  KCC had been implementing 20mph schemes in Kent and had 50 schemes covering over 800 roads. In addition, all new residential developments were designed to keep traffic at 20mph although they were not always signed as such to avoid unnecessary sign clutter. The County’s current policy allowed the introduction of 20mph schemes at any location where such measures could be justified in crash savings terms or via the Member Highway Fund (MHF) providing they met implementation criteria as set out in DfT Circular 01/2013.


(4)       The DfT published new advice on the implementation of 20mph schemes in its circular 01/2013 in January 2013 which contained guidance on the setting of local speed limits. There were two distinctly different types of 20mph speed restrictions which were limits, which relied solely on signing, and zones which required traffic calming to reduce speeds. Highway Authorities had powers to introduce 20 mph speed limits that applied only at certain times of day. The variable limits might be particularly relevant where a school was located on a major through road that was not suitable for a full-time 20 mph zone or limit.


(5)       The report included details and results of Primary School Speed Reduction Scheme Trials.  Evidence showed that schemes which combined 20mph limits with traffic calming measures to reduce speeds had proved very successful in reducing causalities by around 40% to 60%.  When only signing had been used the overall benefits were significantly less. 


(6)       The current safety record of the existing 20mph schemes in Kent which were a mix of both limits and zones showed that casualties recorded on 20mph roads in Kent as a proportion of all roads were 2% less than the national average.


(7)       From 1 April 2013 Kent County Council became responsible for a number of Public Health functions. One of those was the Health Improvement for the population of Kent – especially for the most disadvantaged.  There was evidence that 20mph schemes did encourage healthier transport modes such as walking and cycling as in Bristol, where preliminary results indicated increases in levels of walking and cycling of over 20%. An increase in the implementation of 20mph schemes could assist in the outcome of reducing obesity in adults and children in Kent and improving the overall health of the population.


(8)       Kent Police would not support 20mph speed limits unless the average speed of vehicles was 24mph or less, as research had shown that signed only 20mph limits where natural traffic calming was absent had little or no effect on traffic speeds and did not significantly reduce accidents.  They would also not support the introduction of 20mph zones without sufficient traffic calming measures being in place and of appropriate design, that reduced the speed of most traffic to 20mph or less thereby making them self-enforcing.


(9)       Currently 20mph schemes were funded either from the County’s Casualty Reduction Programme or via the Members Highway Fund. The total Casualty Reduction Programme budget for 2013/14 for new schemes was £800k which goes to fund many different types of safety engineering measures across the county. The cost of any 20mph scheme would vary due to the location and objectives of the scheme. It was estimated that the typical capital cost of a 1km length of 20mph speed limit (signing only) was £1,400 and a 1km length of 20mph zone (including traffic calming) was £60,000.  Revenue costs associated with any scheme would need to be considered including Traffic Regulation Orders, design, consultation, engagement, marketing, monitoring, on-going maintenance of infrastructure and enforcement.


(10)     As with many highway issues there was no national prevailing view as to the policy a local Highway Authority should adopt regarding 20mph schemes. The issues were complex and there were many pros and cons to the various options.  The evidence presented did give some clear indicators that the benefits of 20mph zones were much more effective than signed only limits, providing greater speed and casualty reductions.  Experience in Kent had shown that once traffic calming had been installed it could become very unpopular. Whilst calls for the introduction of blanket 20mph schemes were heard, the costs involved in installing blanket 20mph across Kent were prohibitive and, given current financial restraints, the existing philosophy of introducing bespoke targeted road safety schemes was a more efficient way of achieving casualty reduction.


(11)     The results of the trials conducted outside several primary schools in Maidstone showed that speeds outside the schools at picking up and dropping off times were already low and would meet with DfT criteria for a signed only 20mph limit.


(12)     RESOLVED that a new policy on 20mph schemes be supported to:-


a)            implement 20mph schemes where there was clear justification in terms of achieving casualty reduction as part of the on-going programme of Casualty Reduction Schemes;


b)            identify locations for 20mph schemes which would assist with delivering targets set out in Kent’s Joint Health Wellbeing Strategy; and


c)            enable any schemes that could not be justified in terms of road safety or public health benefits but were locally important to be funded via the local County Councillors Member Highway Fund.  All schemes must meet implementation criteria as set out in DfT Circular 01/2013.

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