E&I: 20mph proven safer, previous UK report wrong

Monday 13 August 2018

A report published last year in the UK that said lower speed limits were proven to be more dangerous has been "comprehensively discredited", the States has said.

This comes as debate has continued over Environment & Infrastructure's controversial plans to reduce the speed limit on over 80 new roads around the island.

Those roads are mainly around community hubs and schools, however have been met with some resistance, particularly since the plans are not set to head to debate.

One of the arguments being made against the proposals pointed to a UK study which claimed a "council was forced to admit" that changes it made to reduce speed limits to 20 were more dangerous, as reported in the Telegraph.

A graph published by the Royal Society for the Prevention of Accidents.

And while no roads would newly be reduced to 20mph in Guernsey, the States have released a statement saying that study was false and misleading.

"The April 2017 report that the Telegraph article was based upon was commissioned by the new council administration in Bath and North East Somerset (that had opposed the introduction of 20mph limits when in opposition) and was quickly and comprehensively discredited as false and misleading by national road safety organisations and independent analysts," a spokesperson for E&I said.

"The report was found to be compromised by flawed methodology, selective inclusions and omissions, misrepresentation of data, the perception of bias, and the failure to comply with local authority ethical standards and DfT guidance.

"In July 2017, the council’s own Transport and Environment Policy Development and Scrutiny Panel declined to endorse the report and decided to take no action on it. That the report’s discredited findings were nonetheless picked up and further sensationalised by national newspapers is therefore disappointing."

A report referenced by the States in its statement, read more here.

Environment & Infrastructure also pointed to a number of other sets of analysis to back up their statement. It said objective analysis of the data showed the introduction of 20mph speed limits in Bath and Bristol resulted in significantly reduced collisions and casualties – for example a 28% reduction in collisions and a 23% reduction in casualties within the 20mph limits in Bath.

Additionally, another study in Warrington reported a 25% reduction in casualties after the implementation of a 20mph limit.

The spokesperson continued: "The draft proposals simply aim to make the long-established local policy of 25mph limits in built up areas more consistent. The Island Development Plan identifies main centres, and these are areas that are already characterised by housing, shops, doctors’ surgeries etc. In other words, these are places with lots of people moving about, and people movements in these areas are likely to increase over time as they will also be the focus points for future similar development.

"Cross-referencing existing speed limits with the IDP map showed several areas where these factors were inconsistent with each other – in other words, areas with high volumes of people movements but also higher speed limits."

Today was the deadline for people to make their opinions on the proposals known to the States. It was asked by some deputies for an extension to be made to that period, however it closed on its originally set date today.

Some of those anonymised consultation responses will be published as part of the final report, which will also include other relevant local data used to inform the eventual decisions.

The full draft proposals can be found here.