In December 2017, various newspapers published articles with variations of "Streets where more people died AFTER 20mph limit came in ...but councillors say it's too expensive to scrap it". They had picked up on an article in the Bath Chronicle about a report submitted by a Bath and North East Somerset Council officer to their Scrutiny Committee in July 2017. In fact the committee rejected the report and took no action as a result of it.
In fact the report did NOT include any details of "deaths" and only compared "killer or seriously injured" across various wards. In doing so it was comparing very small numbers such as 0.8 and 0,6 for previous and after periods. Any statistician will tell you that such comparisons have no statistical significance and are heavily influence by the randomness of crashes rather than representing any trends.
However we did a thorough analysis of the results in the report and these show that :-
- Crashes in the 20mph limits had reduced by 28% in Bath.
- Casualties in the 20mph limits had reduced by 23% in Bath.
- The number roads with average speeds at or above 24mph had reduced by 43% when 20mph was implemented.
- The number of roads with average speeds at or above 26mph had reduced by 78% when 20mph was implemented
This was fully referenced at the time in our blog article entitled "FREDDIE STAR ATE MY 20MPH HAMSTER IN BATH" in homage to the equally dubious historical articles in the media about Freddie Star's culinary preferences.
This blog referenced independent responses to the articles and report, as well as our detailed article where "WE CRITIQUE A RECENT REPORT ON 20MPH AREAS BY BATH AND NORTH EAST SOMERSET COUNCIL"
Therefore before believing any comments about Bath 20mph increasing casualties then we suggest you read the above articles.
Note that on 28th January 2018 we submitted a Freedom of Information request to the council. These asked for details of the 38 killed or serious casualties that we highlighted but not detailed in the report. To date (May 6th) this information has not been provided.
However we now have that information in detail .
Let’s be perfectly clear. Having obtained the full details of the KSIs for the period that the BANES report referenced in The Sun covered we can confirm that there were only 3 crashes which resulted in fatalaties.
1 fatality on a 30mph road 14 months before being set at 20mph. A driver lost control
1 fatality on a 30mph road 32 months before being set to 20mph. A motorcyclist mounted a pavement and hit a wall.
4 fatalities on a 20mph road in one incident 14 months after being set at 20mph when a runaway truck hit pedestrians and cars when its brakes failed on a hill.
So we now know that :-
There were no fatalities on 20mph roads in the 12 months after being changed from 30mph
There was one crash after 14 months which caused 4 fatalities. However this was totally unrelated to the speed limit.
Hence there is absolutely no grounds for suggesting that “20mph limits may be causing more deaths”
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