Blog by Anna Semlyen 20’s Plenty for Us National Campaign Manager June 2019
At the end of June, the Department for Transport (DfT) report some irrelevant statistics on speeding. Note firstly that the 10 sites of 20mph roads are unrepresentative free-flow locations with no traffic calming or other speed restricting features which tend to be through-roads. Yet most 20mph limits are side roads.
Jesse Norman MP, the Minister for Transport has written to Councils saying the “WS Atkins report confirms public support for 20mph”. Many Local Authorities are now reviewing 20mph policies and re-interpreting DfT guidance.Read more
20’s Plenty for Us welcomes the publication of the long-awaited DfT Evaluation of 20mph limits. It confirms the public support and acceptance of 20mph limits but has failed to meet the original DfT objectives or provide increased evidence on how to make our streets safer.Read more
...or why unrepresentative data is not reliable.
If you don't have a TomTom device in your vehicle then you may be surprised that if you live in one of the places recently researched by Atkins for the their Evaluation of 20mph limits then it doesn't matter how much you keep within the speed limit your considerate driving was completely ignored. And you wouldn't be alone. The report estimated that the actual number of drivers who were also ignored were in the 97% of vehicles who's speed they never measured.
Atkins and DfT decided that in order to gather information on vehicle speeds in 20mph streets in 12 case study 20mph areas and compare them with 3 other 30mph areas then they would use data captured from high end TomTom SatNavs or vehicles with in-built TomTom in-car devices. This is termed Floating Car Data (FCD).
You may therefore wonder just how accurate and representative their statistics and research were if it only included 3% of vehicles. We did as well, so we did some of our own research.
Today the government published its long awaited report evaluating 20mph limit implementations. We welcome the report. It has been a long time coming since 2014 when it was commissioned.
And in that time there have been nearly half a million casualties on streets with a 30mph limit.
The report only evaluated a small number of case studies which in themselves only covered part of an authority. There are some useful indicators in the report, particularly around the negative aspects of police failing to routinely enforce 20mph limits and the need for national engagement and awareness on the benefits of reducing speeds below 30mph in residential and other roads.
However, we have major reservations about the primary data used in the report around speed reductions and the complete failure of the study to look at sufficient casualty figures to be able to draw any conclusions that would be statistically credible. These were key reasons for the commissioning of the report and we are amazed at the choice of data measured which appears to be based on measuring what is available rather than what is meaningful.Read more
IAM are not so RoadSmart in their interpretation of the latest DFT report on speed limit compliance on 20mph roads
The annual report on speed limit compliance from the DfT has been seized upon by IAM RoadSmart as evidence of the public being “confused” about 20mph limits. In fact the roads in the report are atypical of most 20mph roads and even then show increasing compliance on these roads.Read more
Our view is that the Cycling and Walking Investment Strategy will fail in its aim to create a walking and cycling nation. Our response follows :-