Please confirm the date of and reason for the reduction of the speed limit on A406 Hanger Lane near Greystoke Gardens N/B before camera 6528 to 30mph from 40mph. Please confirm why the speed limit increases back up to 40mph on A406 near Brunswick Road N/B on the final approach to Hanger Lane gyratory. Please confirm why the 30mph sign before Greystoke Gardens is only a 30cm diameter circle while the 40mph sign that follows it before Brunswick Gardens is a 60cm diameter circle, and the 30mph on the opposite carriageway S/B before camera 6529 is likewise a 60cm diameter circle. Please confirm why the 30mph sign on the N/B carriageway is sited only 57ft before camera 6828 while the larger 30mph sign on the S/B carriageway is sited an some 205 ft before camera 6529, while another repeater 30mph sign of 30cm diameter is sited 59 ft before camear 6529 . Road safety charity Brake states that motorists need 12 m (39ft) to react to any road sign and the stopping distance at 40mph is 120ft - therefore motorists would need 30ft braking distance to reduce speed from 40mph to 30mph. Please confirm how this is physically possible when the 30mph speed limit sign is sited only 57ft from the camera, leaving only 18ft braking distance after the reaction distance of 39ft. Please confirm why after the twin 30mph terminal signs at junction of N Circular Road with Popes Lane, there are no repeater signs for around 1.6 miles on Hanger Lane until a small 30cm diameter one on a lamp post before a camera near Hillcrest Road and another small 30cm diameter one 18ft from Greystoke Gardens (such that the speed limit reminder would not protect this junction from any motorist exceeding it) If TfL's primary concern in speed limit signage is road safety, why are the signs along Hanger Lane, where the speed limit varies between 40mph and 30mph, not bigger and more frequent ?

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TfL Ref: 2678-1819

Thank you for your request received by Transport for London (TfL) on 14 January 2019 asking for information about speed cameras, speed limits and signage on the A406 at Hanger Lane. I sincerely apologise for the delay in replying.

Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy. I can confirm that we hold the information you require. You asked:

Please confirm the date of and reason for the reduction of the speed limit on A406 Hanger Lane near Greystoke Gardens N/B before camera 6528 to 30mph from 40mph.

Please confirm why the speed limit increases back up to 40mph on A406 near Brunswick Road N/B on the final approach to Hanger Lane gyratory.

Please confirm why the 30mph sign before Greystoke Gardens is only a 30cm diameter circle while the 40mph sign that follows it before Brunswick Gardens is a 60cm diameter circle, and the 30mph on the opposite carriageway S/B before camera 6529 is likewise a 60cm diameter circle.

Please confirm why the 30mph sign on the N/B carriageway is sited only 57ft before camera 6828 while the larger 30mph sign on the S/B carriageway is sited an some 205 ft before camera 6529, while another repeater 30mph sign of 30cm diameter is sited 59 ft before camera 6529 . Road safety charity Brake states that motorists need 12 m (39ft) to react to any road sign and the stopping distance at 40mph is 120ft - therefore motorists would need 30ft braking distance to reduce speed from 40mph to 30mph. Please confirm how this is physically possible when the 30mph speed limit sign is sited only 57ft from the camera, leaving only 18ft braking distance after the reaction distance of 39ft.

Please confirm why after the twin 30mph terminal signs at junction of N Circular Road with Popes Lane, there are no repeater signs for around 1.6 miles on Hanger Lane until a small 30cm diameter one on a lamp post before a camera near Hillcrest Road and another small 30cm diameter one 18ft from Greystoke Gardens (such that the speed limit reminder would not protect this junction from any motorist exceeding it) If TfL's primary concern in speed limit signage is road safety, why are the signs along Hanger Lane, where the speed limit varies between 40mph and 30mph, not bigger and more frequent ?

Managing vehicle speeds is an essential element of the Mayor’s Vision Zero ambition to eliminate deaths and serious injuries on London’s roads by 2041. Lower vehicle speeds have been proven to reduce the frequency and severity of collisions and are essential to support increased active travel. If a pedestrian is hit by a vehicle at 20mph they are about five times less likely to be killed than if they were hit at 30 mph. Inappropriate speed is a factor in up to 37 per cent of collisions resulting in death or serious injury on London’s streets.

The speed limit on the A406 varies, but there have been no recent changes to speed limits, except to support roadworks around the site at Power Bridge, south of Pope’s Lane, near Gunnersbury Roundabout.

We consulted upon making the 40mph section of Gunnersbury Avenue between Popes Lane and Gunnersbury Roundabout 30mph in 2016, and we will be permanently lowering the speed limit from 40mph to 30mph as part of a safety scheme which is currently being constructed. Details of the scheme can be found on the web link below:

https://tfl.gov.uk/travel-information/improvements-and-projects/a406-gunnersbury-avenue

The consultation on the speed limit change can be found here:

https://consultations.tfl.gov.uk/roads/gunnersbury-avenue/

The signs referenced in questions 3 and 4 are advisory signs warning that a camera may be ahead, and reminding of the speed limit. There should be no reaction or braking distance required for drivers obeying the speed limit.

The Traffic Signs Regulations and General Directions 2016 do not permit the erection of speed limit repeater signs when the speed limit is 30 mph and the carriageway is lit by a system of street lighting, so the use of repeaters as described in item 5 would be unlawful.

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

Sara Thomas

FOI Case Management Team

General Counsel

Transport for London

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