The case for a 40mph speed limit

A report by our volunteer transport specialist, Malcolm Smith

figure is [ ] brackets refer to references at the bottom of the page. SDN means our organisation South Downs Network


This paper sets out the case for a 40mph speed limit on all roads within the South Downs National Park [except on A roads and trunk roads]. This report considers road user casualties, speed limits, the need to encourage ‘active travel‘ movement within the Park, supporting the need to reduce the speed of traffic on minor roads.

Road user casualties and speed

There is clear evidence that speed of traffic is a significant contributor to fatalities amongst pedestrians and cyclists. Recent Government data shows vulnerable road user casualties such as pedestrians and cyclists are disproportionately high compared the amount of travel they do: pedestrians and cyclists account for 30% of fatal road casualties.[1]

Moreover, more than half [56%] of pedal cycle casualties occur on rural roads compared to 29% of traffic.[2] Similarly rural roads have 56% of road user fatalities but only 45% of traffic [2021 data].[3]

In 2021, 70% of pedestrian and 42% of pedal cyclist fatalities were hit by a car.[4]

Speed of traffic is factor in the number of fatalities as well. Police recorded that in 2021 exceeding the speed limit was a contributory factor in 19% of fatalities and travelling too fast or exceeding the speed limit was a contributory factor in 25% of deaths.[5]

Speed limits

Guidance and Current Policy

National Guidance

Government guidance on setting speed limits is set out in DfT Circular 01/2013.[6]

The guidance makes specific reference to speed limits in national parks as the extract below shows:

“a speed limit of 40 mph may be considered for roads with a predominantly local, access or recreational function, for example in national parks or areas of outstanding natural beauty (AONB), or across, or adjacent to, unenclosed common land; or if they form part of a recommended route for vulnerable road users. It may also be appropriate if there is a particular collision problem.”

The guidance also adds “We would welcome applications for zonal rural speed limits, usually 40 mph zones, for example in national parks [our bold] or AONBs or on other networks of minor rural roads where speeds are already in line with such a limit. Such zones would include entry treatment and painted repeater roundels. The Department is keen to consider the effectiveness of such zones in reducing speeds and signing requirements.”

In addition, “It is government policy that a 30 mph speed limit should be the norm in villages. It may also be appropriate to consider 20 mph zones and limits in built-up village streets.”

So, there is a clear steer towards reducing speed limits in national parks, where appropriate.

In the Select committee Transport, Local Government and the Regions report of June 2002, it states:

“The Department decided that with the information at hand it was not possible to set a lower national limit. Country lanes could not be legally defined and speed signs would be intrusive. If set too low respect for limits as a whole would be diminished. These arguments were not considered convincing by those who submitted evidence to the inquiry. Many memoranda which we received reflected the view that there have to be lower limits on country lanes. These could be readily defined as C and Unclassified roads. A limit of 40 mph would curb the worst excesses and provide a little more safety for those taking a stroll, or riding or cycling. We recommend that guidance to local authorities indicate that 40 mph be the speed limit on C and Unclassified roads. Research should be undertaken into the best ways of enforcing such a limit. Some of the better quality, wider C and Unclassified (where a higher speed is appropriate) might be reclassified as B roads. If a 40-mph limit were introduced on minor roads it may be possible to increase the limit for HGVs on A and B roads from the present 40 mph.” [bold from original report]

It does not appear that the research on enforcing 40mph speed limits on C and Unclassified roads has been undertaken. Nevertheless, we consider setting 40mph speed limits on appropriate roads is the right approach for the reasons set out in this paper.

Local Highway Authorities Policy

The three highway authorities in the National Park have policies relating to setting speed limits.

East Sussex County Council

ESCC has guidance on the issues considered by the Council on speed limit changes but there is no specific reference to such changes in the SDNP. However, ESCC Local Transport Plan 3 [2011-2026] supports:

“Lower speed limits on A or B class roads and in villages where speed limits are 40mph or more and establish 20 mph zones where they meet the current council criteria and to encourage more people to walk and cycle”.

West Sussex County Council

WSCC has guidance on the issues considered by the Council on speed limit changes but there is no specific reference to such changes in the SDNP. WSCC Road Safety Framework [2016 – 2026] notes:

“In geographical terms there are four significant groups including Rural Routes Mainly A & B class roads, speed limits 50mph and above 39% of all KSI, (53% of fatalities)”

In addition, WSCC recognises [RSF]:

“Road safety and the outcomes for those involved in crashes could be improved by reducing the contributing factors and chain of events that increase the risk of crashes happening in the first place”

Hampshire County Council

HCC has a general policy to focus on speed limit changes in relation to reducing road user casualties.[7]

South Downs National Park Authority

As it is not a highway authority SDNPA does not have powers to set speed limits. However, in the “Roads in the South Downs” report of 2015 for SDNPA and the 4 local highway authorities [Brighton and Hove, ESCC, WSCC and HCC] there is no specific reference to speed limits but refers to preferred speeds taking into account a number of variables and a methodology for plotting preferred speeds against actual speeds.

Other Policy

Association of Directors of Environment, Economy, Planning and Transport [ADEPT]

In March 2022, ADEPT put forward a new policy position on speed management. It called for urgent changes in how road speed is managed, especially in rural areas.

In its new policy position on speed management, ADEPT called for the adoption of the 2019 Department for Transport Safe System approach to be adopted to manage road speed, rather than national speed limits.

Most fatalities occur on rural single carriageways with the 60mph limit a particular cause for concern, stated ADEPT.

The safe system approach adopts five key elements: safe road use, safe speeds, safe vehicles, post-crash care and safe roads and roadsides.

ADEPT argued that using this system to set road speed would encourage safer driving, as local highways authorities (LHAs) would have the ability to set an appropriate speed.

ADEPT also called for providing local highways authorities with longer-term funding certainty to implement speed management changes and make road safety improvements and the development of a speed management toolkit to enable greater uniformity across LHAs and provide more consistency for drivers.

ADEPT also requested the Government to enable speed management decision-making based on wider benefits, including for cyclists and pedestrians, rather than using only serious injury and mortality statistics. Alongside the adoption of a safe system approach, this would ensure speed management is appropriate for all road users, it stated.

Recent Research on Traffic Speeds

Brake/Direct Line study

In a 2019 study by Brake and Direct Line Insurance, 68% of drivers found it acceptable to drive above the speed limit on rural roads [the national speed limit is 60mph on single carriageway roads]. Nearly half (48%) of drivers said that they had driven faster than the speed limit on a single-carriageway rural road in the past year.[8]

In an earlier Brake/Direct Line study from 2009, 70% of drivers agreed that the national speed limit of 60mph should be lower on rural roads.

Surrey County Council study

A study by consultants Agilysis for Surrey County Council in 2020[9] showed that higher speeds result in increases in collisions and that also the public are generally supportive of lower speeds.

Collision rates on rural roads with lower average and 85th percentile speeds are lower than roads with higher average and 85th percentile speeds.

The study confirmed the link between collision risk and high driven speeds.

The analysis demonstrated clear increases in collision densities when speeds were higher. This was even more prominent when 85th percentile speeds increased by one mile per hour. The most serious collisions (involving a KSI casualty) were even more greatly influenced by increases in speeds.

Examples of Lower Speed Limits in National Parks and elsewhere

In East Sussex, Ashdown Forest AONB introduced a 40mph speed limit on minor forest roads in 1997.

In Hampshire, the New Forest National Park has a uniform 40mph speed limit which was introduced on all New Forest roads apart from fenced major A roads. This has had the most significant effect on reducing animal deaths with annual casualty statistics being slashed compared to pre-40mph limit years. Also speed limits are lower in some areas of the New Forest.

There is also a 40mph speed limit on Dartmoor National Park’s fenced roads and there has been support for reducing the 60mph speed limit on unfenced roads to reduce the number of animals killed on Dartmoor.

In addition, Surrey County Council has announced plans to pilot speed limits of 20mph and 30mph on roads that were previously 60mph, in what is thought to be a UK first.

The pilot area covers 80 square miles south of a line from Guildford to Dorking.

Policy Support for Active Travel

SDN supports more active travel to and within the National Park. Reducing the speed of traffic on relatively minor roads can encourage more people to walk and cycle in the Park. In a wider policy context, the Government published its strategy for improving cycling in England in “Gear Change” [10]. However, this was very much focused on improving and expanding cycling in urban areas. There was relatively little on addressing cycling in rural areas although there is recognition of the wider decarbonisation and health agenda.

Quiet Lanes

In legislation from 2006, the Government allowed authorities to designate unclassified roads in rural areas to be Quiet Lanes, where the traffic volume should be less than 1000 vehicles per day. Quiet Lanes are routes where visitors and locals can enjoy the natural surroundings and use them for activities such as horse riding, cycling, jogging and walking. However, the idea is not to restrict motor vehicles on these routes but to encourage considerate use of the road so they can be shared and enjoyed by all.

Schemes have been put in Suffolk, Norfolk, Kent and Essex with evidence that traffic volumes and speed have decreased in the Lanes.

Quiet Lanes in the SDNPA area have the potential to be complementary to an area-wide 40mph speed limit.









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