Serviceability of Traffic cameras on A4 from Hounslow to Brentford
Request ID: FOI-0834-2223 Date published: 27 July 2022
You asked
We would like to know the seviceability of the traffic cameras on the A4 from Hounslow into Brentford. Apart from a recent fatal collision on the A4 by Osterley, residents complain of loud racing.cars late at night which should be limited if the Traffic cameras are working. This seems very dangerous.
We answered
Our ref: FOI-0834-2223/GH
Thank you for your request received by Transport for London (TfL) on 6 July 2022 asking for information about traffic cameras on the A4.
Your request has been considered under the requirements of the Freedom of Information Act 2000 and our information access policy. I can confirm that we do hold the information you require.
There are 35 cameras on the A4 from South Kensington to the M25.
The cameras are a range of
Red Light & Speed on Green, Spot Speed Red Light Dual Speed
All of the cameras are digital and are permanently live.
Transport for London (TfL), the Metropolitan Police service (MPS) and the Mayor of London are committed to delivering a Vision Zero approach to road danger reduction, to ultimately rid London's roads of death and serious injury. Speed is a key source of road danger and the single most important factor in the likelihood and severity of a collision. Safety cameras are one of the ways we can use to effectively manage and enforce speed limits in London.
TfL funds, operates and maintains London’s safety camera network, which helps prevent a significant number of deaths and serious injuries each year. TfL provides funding to the MPS and City of London Police to enforce the cameras.
In accordance with the FOI Act, we are not obliged to supply you with information on any cameras which are currently not in service. This is subject to a statutory exemptions to the right of access to information under Section 38(1)(b); Health and Safety – endangerment to the safety of any individual, and Section 31(1)(a) Law Enforcement which relates to all aspects of the prevention and detection of crime.
Section 38 exemption is applied to all requests on safety camera performance as disclosure of the information requested would be likely to adversely affect the safety and security of motorists, pedestrians and other road users. The purpose of safety camera enforcement is to deter motorists from breaking the law and travelling at speeds in excess of the stated limit. Speed compliance relies on this deterrent effect.
Section 31 exemption has been applied as provision of this information would confirm whether it’s likely that restrictions will be enforced as well as potentially identifying where the enforcement is in operation. The purpose of enforcement is to deter drivers from contravening restrictions so is focused on those areas of greatest risk, where compliance is low and where other traffic management initiatives have been unsuccessful. Disclosing information which reveals the activation status of safety cameras as well as the likelihood of enforcement would lead to a decrease in compliance with traffic restrictions and therefore increase unlawful driving.
When considering the prejudice test and taking into account any harm likely to arise if the requested information were put together with other information already published into the public domain (commonly known as the ‘mosaic effect’) we believe that by disclosing this information this would enable others to build up a database of enforcement camera functionality as well as attempt to predict when cameras may or may not be operational. Were there to be a perception that some camera sites were not operating, whether or not that perception is misguided, the likely result is that there would be an increase in dangerous and unlawful driving through those areas. Thousands of casualties are reported each year, both fatal and injured, with excess speed being determined as a major contributory factor. Inappropriate speed also magnifies other driver errors, such as driving too close or driving when tired or distracted, increasing the chances of these types of behaviour causing a collision.
Disclosure of this information to you has to be regarded as a disclosure to ‘the public at large’. We consider that the likelihood of prejudice is particularly high because there is a separate and well-established network of information available online which deliberately seeks to undermine legitimate enforcement of this nature. Therefore, given the significant concerns we have that provision of this information would be likely to endanger the public, we consider the exemption to be engaged.
The use of these exemptions is subject to an assessment of the public interest in relation to the disclosure of the information concerned. We recognise the need for openness and transparency by public authorities, but in this instance feel that balance lies in favour of withholding the information to ensure that we’re able to continue to comply with our Network Management Duty and ensuring the safety of all road users. There remains a very strong public interest in maintaining the effectiveness of speeding prevention measures and the subsequent safety benefits they bring. Protecting the overall deterrent effect in relation to speed cameras is paramount to ensuring maximum compliance which, in turn, helps to continue the reduction in road collisions that lead to injury and/or fatal outcomes. We therefore conclude that the overwhelming public interest falls in favour of maintaining the exemptions.
If you are not satisfied with this response please see the attached information sheet for details of your right to appeal.
Yours sincerely
Graham Hurt FOI Case Officer FOI Case Management Team General Counsel Transport for London
