Request ID: FOI-4427-2324 Date published: 16 April 2024
You asked
Hi. Who is the most appropriate contact to correspond with regarding the announced plans to reduce the speed limit on the A406 in North London? Other than a brief mention as general policy, I am unaware of any announcements or consultations on this specific issue, nor is the TfL website much help. I would also be grateful if you could provide me with the details of the plans, the data upon which this proposal has been based, and where and how we can submit our opinions.
More specifically:
1) I understand there have been 208 serious incidents on the A406, but there is no mention of whether any of these have been attributable to vehicles travelling between 40 and 50 mph. Is this the case? Clearly, all these 208 incidents can easily be examined individually, and reports from the police, witnesses, and drivers are very likely to include the likelihood of speeds over 50 and/or other driver errors (ie nothing to do with the current limit). Has this been done and what were the findings? And if not, why not?
2) Existing cameras can also be programmed to record speeds over 40 (without prosecuting) and then correlated with any subsequent incidences. Has this been done yet and what were the findings? And if not, why not?
3) A lot of the road furniture already has the capability to adjust the speed limit most appropriate to driving conditions (weather, daylight, traffic density/congestion, etc). Has this been examined as an alternative option and what were the findings? And if not, why not?
4) TfL appears to be about to impose more restrictions on literally hundreds of 000's of vehicles because of these 208 incidents, a tiny fraction of occasions in which the legal speed limit may well have been irrelevant anyway. How many vehicle journeys happen on the affected e stretch of the A406 in an average day and month? How many of those journeys involve some sort of speeding offence over 40 mph? How many over 50 mph? And how many accidents and/or incidents by different categories happen?
5) What consideration has been given for other unintended consequences, such as displacement into other roads without speed cameras, and/or geographically shorter routes, and/or poorer quality behaviours by drivers who are more tired and frustrated because of their longer journeys, and/or other considerations? And what were the findings? And if not why not?
Please treat these questions as an FOIA request and I look forward to hearing from you.
Clarification received 07/03/2024:
Please find attached a TfL letter posted on local social media.
More importantly, there is no reason not to have already responded before now to my other questions (as below)– especially with respect to how to object to the proposed changes to the speed limits – and I expect as prompt as response as possible please.
We answered
TfL Ref: FOI-4427-2324
Thank you for your request of 14th February 2024 – as clarified on 7th March 2024 - asking for information about speed limits on the A406.
Your request has been considered in accordance with the requirements of the Environmental Information Regulations (EIR) and our information access policy.
I can confirm that we hold some of the information you require. Your questions are answered in turn below:
Question 1: I understand there have been 208 serious incidents on the A406, but there is no mention of whether any of these have been attributable to vehicles travelling between 40 and 50 mph. Is this the case? Clearly, all these 208 incidents can easily be examined individually, and reports from the police, witnesses, and drivers are very likely to include the likelihood of speeds over 50 and/or other driver errors (ie nothing to do with the current limit). Has this been done and what were the findings? And if not, why not?
Answer: TfL does not hold the exact information requested as we do not necessarily receive details of the speed at which a vehicle was travelling when a collision occurs. It is not a requirement from the Department of Transport that the police report the speed a vehicle was travelling in the STATS19 record they produce. In most cases this information would be difficult to record as the police would have attended the collision after it has occurred. It is possible for the police to add a free text description to a collision record, but as these can contain personal details such as names and addresses, or allegations of crimes, these may be redacted and hence unavailable for analysis by TfL. That said, we have reviewed our records of collisions on the A406 between Callard Avenue to Hall Lane for the period October 2020 to September and have found 23 instances where speed was recorded as a contributory factor. These collisions resulted in 33 people being killed or injured (1 fatal, 3 serious injuries, and 29 slight injuries). This may not be a comprehensive picture of all speed related incidents for the reasons outlined above. Note further that we do not receive details of contributory factors for self-reported collisions made by members of the public. In London, around 40% of our records are self-reports.
You may be interested in the following pages of our website which provide more information about collisions in London and measures to reduce fatalities and serious injuries:
Question 2: Existing cameras can also be programmed to record speeds over 40 (without prosecuting) and then correlated with any subsequent incidences. Has this been done yet and what were the findings? And if not, why not?
Answer: In theory existing speed cameras could have their threshold changed to capture that data, but this would cause severe disruption to the enforcement operation with the Metropolitan Police Service through non-enforceable speeds being recorded that we could not separate out. The cameras are there for the purpose of enforcing the speed limit and thus are set to National Police Chief Council thresholds. They are not a tool for conducting speed surveys.
Question 3: A lot of the road furniture already has the capability to adjust the speed limit most appropriate to driving conditions (weather, daylight, traffic density/congestion, etc). Has this been examined as an alternative option and what were the findings? And if not, why not?
Answer: Variable speed limits are installed on motorways. This would not be feasible to implement in different road environments with more concentrated junctions. Even if it were, it would require considerable investment. More details on setting local speed limits can be found here - Setting local speed limits - GOV.UK (www.gov.uk)
Question 4: TfL appears to be about to impose more restrictions on literally hundreds of 000's of vehicles because of these 208 incidents, a tiny fraction of occasions in which the legal speed limit may well have been irrelevant anyway. How many vehicle journeys happen on the affected e stretch of the A406 in an average day and month? How many of those journeys involve some sort of speeding offence over 40 mph? How many over 50 mph? And how many accidents and/or incidents by different categories happen?
Answer: For the route A406 between Callard Avenue to Hall Lane, the Department for Transport’s AADF (Annual Average Daily Flow) data recorded 96,163 vehicles per day in 2022 and 90,262 vehicles per day in 2020. TfL does not hold data on speeding offences – this is a matter that the police enforce. For information on accidents, please see our response to Question 1 and the Collisions Map referred to via the Road Danger Reduction Dashboard.
Question 5: What consideration has been given for other unintended consequences, such as displacement into other roads without speed cameras, and/or geographically shorter routes, and/or poorer quality behaviours by drivers who are more tired and frustrated because of their longer journeys, and/or other considerations? And what were the findings? And if not why not?
Answer: The London Boroughs of Enfield and Waltham Forest already operate a borough-wide 20mph speed limit so displacement would be unlikely. TfL is aiming for more consistent and steady speeds which in turn should reduce pollution. The Department for Transport’s ‘setting local speed limits’ guidance (link above in answer to Question 3) states the following and therefore challenges the misconception that slower speeds result in longer journey times:
“34) On rural roads there is often a difference of opinion as to what constitutes a reasonable balance between the risk of a collision, journey efficiency and environmental impact. Higher speed is often perceived to bring benefits in terms of shorter travel times for people and goods. However, evidence suggests that when traffic is travelling at constant speeds, even at a lower level, it may result in shorter and more reliable overall journey times, and that journey time savings from higher speed are often overestimated (Stradling et al., 2008). The objective should be to seek an acceptable balance between costs and benefits, so that speed-management policies take account of environmental, economic and social effects as well as the reduction in casualties they are aiming to achieve.”. If this is not the information you are looking for, or if you are unable to access it for any reason, please do not hesitate to contact me.
Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.
Yours sincerely,
David Wells FOI Case Officer FOI Case Management Team General Counsel Transport for London
