Speed limits are introduced to ensure greater road safety and should seek to balance this with accessibility and environmental objectives, improving the quality of life for local communities. Any changes we make to speed limits must adhere to criteria set out by the Department for Transport (DfT).
Speed limits are the maximum speed at which vehicles may legally travel – they are not target speeds. You should always reduce your speed when:
- the road layout presents hazards, such as bends
- you are sharing the road with pedestrians
- there are adverse weather conditions
- you are driving at night – as it is harder to see other road users and possible obstructions.
Balancing the need to travel with overcoming social exclusion and strengthening rural communities are also key, but must be carefully assessed against reducing road traffic. The promotion and education of safe and considerate driving and encouraging road users to adopt appropriate speeds on our roads is also important to the success of speed limits. The responsibility for the enforcement of speed limits lies solely with the police and instances of speeding can be reported to your local police officers tel: 101.
In January 2006 the Department for Transport published guidance circular 01/2006 (now replaced by circular 01/2013) on setting local speed limits which sought a common national approach on the setting of limits, highlighting the need to manage speed in a way that is appropriate for the road function and local characteristics. Following release of this guidance, the Secretary of State ordered a countrywide review of all ‘A’ and ‘B’ classified roads. This review has now been completed in Derbyshire, with changes to speed limits implemented where appropriate.
Speed limits in urban areas
DfT guidance states:
“Urban roads by their nature are complex as they need to provide for safe travel on foot, bicycle and by motorised traffic. Lower speeds benefit all urban road users, and setting appropriate speed limits is therefore an important factor in improving urban safety.”
On roads where a recognised system of street lighting is present (where there are three or more lighting columns not more than 183m apart) the default speed limit will be 30mph, unless there are signs in place indicating a different limit, and will be signed accordingly where the street lights start. Such roads will have a significant degree of frontage development with pedestrian activity and the presence of driveways, junctions, traffic signals and crossings. By law we cannot put in additional 30mph (repeater) signs where street lighting is present.
A 40mph speed limit is generally appropriate on higher quality suburban roads with less frontage development but with side roads, some bends and traffic signals or pedestrian crossings. Repeater signs are required.
In exceptional circumstances 50mph speed limits may be introduced on roads where the environment and characteristics allow this speed to be achieved safely – such as dual carriageways, radial routes or bypasses. Higher speed limits encourage urban through traffic to use routes of this nature rather than less suitable residential streets.
The default speed limit on unlit roads is de-restricted to 60mph on single carriageways and 70mph on dual carriageways and motorways.
Speed limits in rural areas
DfT guidance stipulates that 30mph is considered the norm in villages, based on a simple criteria relating to the density of frontage development and distance:
There should be 20 or more houses on one or both sides of the road, over a length of around 600m. This can be less if the level and density of development exceeds the 20 or more houses criterion. In instances where there are fewer than 20 houses an extra allowance can be given for key buildings – for example, churches, community centres, schools.
A preferred length of 600m is desirable to avoid too many changes of speed limit along the route, which could lead to motorists disregarding the changes.
In the absence of street lighting 30mph repeater signs will be required.
The default speed limit on dual carriageways is 70mph and 60mph on single carriageway roads that have very sparse development, are of a high quality, and have a strategic function. Lowering the speed limit to 50mph can be considered where there are a high number of bends, junctions or accesses and a high level of injury collisions. A speed limit of 40mph may be considered in very exceptional circumstances in an area of outstanding natural beauty or across, or adjacent to, unenclosed common land, or if they form part of a recommended route for vulnerable road users. Such a special application would need however to be done in association with the Department for Transport and discussion with a national park authority.
Speed limits on single carriageway rural roads should take into account the collision history, the road’s function, existing average traffic speed, level of use by vulnerable road users, the road’s geometry and engineering, and the environment, including the level of road-side development.
Terminal signs (at the start of a speed limit) must be positioned as close as practicable to the start of a built-up area. Where forward visibility is restricted, signs may be extended outwards to meet standard forward visibility requirements.
20mph speed limits and zones
20mph speed limits and zones may be considered as an option to reduce vehicle speeds and road traffic casualties in urban areas with particularly high levels of activity by vulnerable road users, such as pedestrians and cyclists, the importance of which outweigh the disadvantages of longer journey times for motorised traffic. Residential areas that have a high injury collision rate involving pedestrians are also given priority when considering the use of a 20mph speed limit. Typical locations would include town centres and around schools that have a large number of pupils walking/cycling to school along busy routes.
Such schemes can have much wider, non-tangible benefits than simply reducing the number of accidents. 20mph speed limits and zones may improve social and health aspects of an area; improving people's perception of where they live and providing wider health benefits such as encouraging walking and cycling.
20mph zones were first introduced in Derbyshire in 2000 and around 25 such schemes have now been adopted countywide. They should be self-enforcing and so are usually only appropriate in areas where speeds are already naturally low or where a suitable package of traffic calming measures can be used to ensure compliance with the speed limit.
There are two forms of 20mph measure available to us. 20mph speed limits are signed only (i.e. no traffic calming measures are used) with the restriction being indicated with terminal signs and at least one repeater sign. 20mph speed limits are similar to other local speed limits and normally only apply to individual or a small number of roads. The absence of any traffic calming measures mean that existing traffic speeds would have to be naturally low to ensure that the lowered limit does not create an unnecessary enforcement burden on the police. Studies into the effectiveness of sign-only 20mph speed limits have shown that they have very little impact on traffic speeds, averaging around a 1mph reduction in traffic speeds following their introduction.
20mph zones cover a defined area of roads and include a package of supportive measures, such as traffic calming, road markings and signing, to achieve compliance.
As the local Highway Authority, we also have powers to introduce 20mph speed limits and zones that apply only at certain times of day. At schools located on major routes where a 20mph speed limit is not appropriate outside of school arrival and dispersal times.
We have a policy of introducing 20mph speed limits and zones sparingly, with casualty reduction being a priority for the selection of such schemes.
Traffic regulation orders
The imposition of any new speed limit, or amendment to existing speed limit, requires a Traffic Regulation Order to be made. This is a legal process which includes a statutory consultation with public bodies such as the police, district and parish councils. A public notice period is also required – where details are advertised both on site and the local press - to give local residents and road users the opportunity to comment on the proposal. Any representations received during consultation must be considered by the cabinet member for highways, transport and infrastructure who may resolve to support the original proposal, amend the proposal (in which case a further round of consultation and public notice would be required) or abandon the proposal altogether.
Once a proposal has been approved, the necessary signs are ordered and arrangements made for them to be in place on a certain date to coincide with the date the order comes into force. The order is then enforceable by the police.
This entire process, from investigation to implementation, can take between six and 12 months to complete.
Introducing a Traffic Regulation Order is both a time consuming and costly process. We receive many requests for speed limits and therefore apply a points-based scoring system to allow such requests to be prioritised. This allows resources to be better targeted at those areas which highlight an issue with collisions. The ranking scheme is included below.
For general enquiries on the provision of speed limits please contact:
Community Speed Watch
Excess speeds alone are unlikely to justify the lowering of an existing speed limit. The speed limit will have been implemented according to Department for Transport guidance and will be appropriate for the character of the road and level of built-up development. The vast majority of drivers will choose to drive at speeds they feel are appropriate and unnaturally low speed limits will be ignored. Compliance could perhaps be achieved by introducing a package of traffic calming measures but, in the absence of a speed-related injury collision history, the expenditure would be difficult to justify.
Enforcement of speed limits lies solely with the police but they too will prioritise their resources based on sites that suffer from a combination of excess speeds and a history of speed-related injuries.
Where speeding is a concern in the local community – and in the absence of any clear road safety problems – residents and parish councils may be able to volunteer for a Community Speed Watch scheme.
Community Speed Watch is an initiative whereby volunteers work alongside the area’s Safer Neighbourhood Policing Team (SNT) to monitor traffic speeds in their community. Volunteers are firstly provided with training on how to operate the speed detection equipment and then given opportunity to carry out speed checks with local officers.
No enforcement action is taken against any driver detected speeding but their details are recorded and a letter sent to the vehicle owner informing them of their speed and requesting that they respect local speed limits. They are also warned that if they are caught breaking the speed limit again they may face a fine and penalty points on their licence.
Community Speed Watch is an effective way of highlighting speeding to individual drivers and reminding them of their responsibility in adhering to speed limits and the consequences of not doing so.
For general enquires on Community Speed Watch, contact your local police office tel: 101.
Speed limit ranking scheme
Table showing speed limit ranking scheme
|Subject||Parameters||Points range||Points scored|
Serious and Fatal
Divided by crash exposure value:
(volume (vpd) x length (m) x 365) x 2
Total collision component score
|Capital scheme or developer funded|
|Enforceability (based upon 85 percentile speed)|
New limit self-enforcing
Supporting engineering features required
Regular police enforcement
|Benefits of scheme to vulnerable road users|
|Benefits to schools|
|Benefits to elderly/mobility impaired|
Benefits to local facilities/businesses
|Effect on emergency services response times|
|Support from residents|
No overall support
Residents not in support
|Support from community and/or special interest groups|
No support forthcoming
|Cost of speed limit, including advertisements and associated works|
£5,000 to £7,500
£7,500 to £10,000
£10,000 to £15,000