Somerset County Council

Apply for a new speed limit


We are responsible for speed limits on all public roads in Somerset, except the M5 and trunk roads (A36 and A303). The reason for providing speed limits is to improve safety for all road users.

We set local speed limits where drivers should adopt a speed which is different from the national speed limit because of local needs and considerations. Local speed limits can be reduced or increased, depending on the conditions and evidence.

The Department for Transport has issued guidance to be used for setting all local speed limits on single and dual carriageway roads in urban and rural areas. 

Our criteria for setting the right limit for any road takes into account existing traffic speed, accident history, the amount of traffic, frequency of junctions, and building development and amenities. Unrealistic speed limits are frequently abused and can prove very expensive and difficult for the police to enforce.

Any changes to, or the implementation of, speed limits should be in accordance with the latest Department for Transport guidance. 

Laws and regulation
These are governed by Department for Transport (DfT) guidance on the Setting of Local Speed Limits (Circular Roads 01/2006).

Speed limits should be evidence-led, self-explaining and seek to reinforce people’s assessment of what is a safe speed to travel. They should encourage self-compliance and not be seen by drivers as being a target speed at which to drive in all circumstances. In deciding an appropriate speed limit for a road, one of the key issues to be studied is the existing speed of traffic - setting speed limits too far below measured traffic speeds is very unlikely to be effective.

Successful 20mph zones and speed limits should generally be self enforcing. Such speed limits are unlikely to be complied with on roads where vehicle speeds are substantially higher than this unless accompanied by traffic calming measures. Research by the Transport Research Laboratory (TRL) showed that where speed limits alone were introduced, speed reductions of only about 2mph were achieved. 20mph speed limits are therefore only recommended in areas where vehicle speeds are already low (24mph or below is recommended) or additional traffic calming measures are implemented.

The standard speed limit in urban areas in 30mph, representing a balance between the mobility and safety of road users, especially more vulnerable groups. These are generally built-up areas where frontage development with individual accesses on both sides of the road exist, such as city streets, towns and residential areas. Hazards, such as junctions, inadequate visibility, pedestrian crossings, schools, recreation grounds and public amenities support the need for a 30mph limit and make it appear sensible to the motorist.

The 40mph limit is used in similar built-up areas to the 30mph limit, but where the traffic hazards cause less risk of accidents. For example, the buildings may be set back from the road and be in an area of lower density, perhaps sometimes with service roads, or grass verges between the road and pavement. Main traffic routes (for example, ring and radial routes) with good width and layout, but with a high proportion of two-wheeled vehicles and pedestrians may be restricted to the 40mph limit. By-passes and other important traffic routes which have become partially developed, or main roads through villages, may also be included in a 40mph limit.

50 and 60
A speed limit of 50mph can be made on high standard roads where the area has become lightly built up with some frontage development. The traffic composition is likely to be light in terms of pedestrian and cycle activity, and crossings are provided by means of subways and bridges. High standard roads with restricted visibility or junctions may be considered for the 50mph limit and rural roads, not necessarily developed, but with features that attract traffic manoeuvres such as cafés, sports grounds and filling stations. Dual carriageways may be restricted to a 60mph limit where some of the above features exist.

We do not have a specific speed limit fund. Some communities and parish councils can apply where the change does not qualify for Local Transport Plan (LTP) funding. Providing speed limits comply with the DfT guidelines, do not conflict with LTP objectives and the parish councils meet the full costs, there is no reason why new limits should not be introduced.


Contact: Roads and Transport Team
Phone: 0300 123 2224
Opening Hours: Monday 8am to 6pm, Tuesday to Friday 8.30am to 5.30pm, Saturday and Sunday closed.

If there is an urgent problem outside these hours and it is a risk to public safety please phone the police on 101.

If you need to visit a highway area office you can find the address of your local office here.

» Indicates required fields

Feedback form
Was this information helpful? »