Alternative speed measures

A Community Speed Watch scheme allow volunteers to monitor the speed of passing vehicles using a speed detection device.

The volunteers record the details of vehicles which are exceeding the speed limit. These details are passed to the Police, who will issue a letter to the vehicle owner, advising them of the dangers of speeding, and reminding them of the law. If three letters are issued to the same vehicle owner, the Police carry out further investigation.

Effectiveness

As Community Speed Watch volunteers are highly visible and make use of a speed detection device, it is usually clear to vehicle drivers their speed is being monitored. This may be enough for many motorists to slow down. Some motorists may mistake the volunteers for police officers.

The ‘community’ element of Community Speed Watch could have a more positive effect on some vehicle driver’s attitudes compared to engineering schemes.

Community Speed Watch may only reduce vehicle speeds when the volunteers are present at the road side. However, there should be a significant effect on vehicle drivers who receive letters as a result of exceeding the speed limit. Other drivers may continue to reduce their speeds at all times, as they might expect Speed Watch to return to the same place, or appear in another area.

Advantages of community speed watch

• Volunteer run
• Equipment and training provided by Cambridgeshire Constabulary
• Community engagement in speeding issues is a different way of changing driver behaviour

Disadvantages of community speed watch

• Drivers can’t be fined if they are recorded exceeding the speed limit
• Drivers may be aware the Community Speed Watch groups can’t issue fines, and will continue to exceed the speed limit
• Requires willing community volunteers to offer their time

Restrictions

• Volunteers must only operate at sites approved by the Police
• Volunteers can only operate in daylight hours

Cost of equipment

• £5,000

The cost is for the Speedwatch unit only

More information from the Police

You can get more information on Community Speedwatch on the Cambridgeshire Constabulary website.

Please note that LHI funding for MVAS signs can not be applied for within the Cambridge City area.

Mobile Vehicle Activated Signs (MVAS) are electronic signs which only become visible when approaching motor vehicles are exceeding a certain speed. The signs normally display the speed limit, however they can also display the actual speed on the sign and these are called Speed Indicating Devices (SID).

MVAS are formed of many bright lights which only turn on when the target motor vehicle is in plain view of the sign.

Effectiveness

MVAS have a short-lived effectiveness in reducing speeds. Unfortunately drivers become too familiar with them when they are situated in one particular location for long periods of time. They can be most effective when positioned near downhill gradients reminding drivers who may be inadvertently speeding.

When MVAS are relocated regularly around different parts of the village or town this can increase effectiveness as drivers will be unaware of where the sign will be next time they travel.

Advantages of mobile vehicle activated signs

• No discomfort or delay experienced by any vehicle user
• Relatively cheap
• Continue to have a positive effect over time if relocated regularly
• Moving between different sites can increase effectiveness

Disadvantages of mobile vehicle activated signs

• Not as effective as vertical interventions
• Too many of these devices could diminish their effectiveness

Considerations

• Parish and town councils would be required to maintain and relocate the signs going forward in accordance with Cambridgeshire’s Highway Asset Management Policy.
• Location of the MVAS needs careful consideration as light pollution can cause concerns with residents
• MVAS must be placed on a straight stretch of road to allow the radar device to accurately judge the speed of approaching motor vehicles

Cost of installation

• £5,750

The cost for the MVAS unit is based on one unit and two new posts.

Please note that costs above are to supply the MVAS, associated mounted equipment, spare batteries, and supply and install a number of posts for the device to be moved around.

We recognise that MVAS can be a popular speed educational tool. Should you wish to apply for permission to use them on the highway please complete this application form and return by post to the address specified or by email to policy.andregulation@cambridgeshire.gov.uk.

You will be required to agree to a Memorandum of Understanding to make sure the sign's correct use on the highway.

Mobile vehicle activation sign request form (opens as a word document)

There are three national speed limits; 30mph on roads with street lighting, national speed limit of 60mph on single carriageway roads and national speed limit of 70mph on dual carriageways and motorways. These national limits are not appropriate for all roads.

The speed limit regime enables traffic authorities, like Cambridgeshire, to set local speed limits in situations where local needs and conditions suggest a speed limit which is different from the standard national speed limit. Buffer zones are becoming ever popular around Cambridgeshire and generally offer a short section of 40mph approaching a village or town’s 30mph limit. This can help to ensure that a driver is travelling more slowly on the approach to the lower limit.

Effectiveness

Changing the speed limit and introducing nothing but a change in sign is very unlikely to ensure driver compliance on its own. If all speed limit signage were taken away, the driver should instinctively know what the speed limit is from the environment: a driver will choose different speeds for a rural road through open countryside and a built up road through a town centre.

Alternatively, the road environment should be such that higher speeds are difficult to achieve because of the nature of the road, e.g. traffic calming is present.

Speed limit options available (Complex)

30mph speed limit / zone

• Will only be introduced in fully developed settlements. Term settlement means 20 properties fronting onto a length of public highway over a distance of at least 600m.
• Read how we define and assess speed limit applications in our Highway Operational Standards April 2023 document (opens as a .pdf) on page 73, section 28.

40mph speed limit / zone

• Generally introduced on the outskirts of urban areas where there is little development and few vulnerable road users.
• Areas of development will generally be set back from the road

50mph speed limit / zone

• Considered for lower quality roads that have a relatively high number of bends, junctions and accesses.
• Also considered where the mean speeds are below 50mph, therefore lower limit doesn’t interfere with traffic flow.

Buffer zone (Non-complex)

• They can be up to 400 metres in length, set at a minimum of 10mph above the settlement speed limit.

Advantages of speed limits and buffer zones

• Relatively cheap
• Nationally recognised signing
• No discomfort experienced by any vehicle user

Disadvantages of speed limits and buffer zones

• Not as effective as vertical interventions
• Effectiveness can be diminished if incorrect limit is installed
• Cost increases when additional measures are required
• Reduction in enforcement can reduce effectiveness
• An inappropriately low speed limit can lead to an increase in poorly judged overtaking and related accidents
• An inappropriately low speed limit is likely to result in speeding issues

Restrictions

• All speed limits must have the full support from the Police.
• All speed limits must comply with Cambridgeshire County Council’s Highways Asset Management policy
• Requires a Traffic Regulation Order

Cost of installation

• Buffer limit - £5,000

The buffer speed limit cost is based on two additional terminal signs and two posts with 2 pairs of repeater signs, installed under two-way lights. There is no provision for lighting the signs.

• Speed limit –
• £14,000 for a new limit up to 0.75km long.
• £16,000 for a new limit up to 1km long.
• £18,000 for a new limit up to 1.25km long.

The speed limit cost is based on changes within a small parish with no street lighting and includes repeater posts and roundels, installed under two-way lights. There is no provision for lighting the signs.

Gateways are designed to highlight the entrance to a Parish, Town or Village and/or change of speed limit. In Cambridgeshire the most common method is through installing gates and village name plates at the entrances to villages, often in combination with the speed limit terminal sign.

Drivers tend to notice and accept the distinction between the two speed limits when there is a more obvious presence on the entrance.

Effectiveness

The speed reducing effect is highest when gateways are first installed. Many drivers subconsciously adjust their speed according to the surroundings, driving more slowly in built up areas and faster in rural areas with open fields. A gateway feature signals that a driver is leaving a higher speed area and entering residential area. However, the benefit can reduce over time as drivers become used to them.

Design

These gates are made from a blend of wood fibre, recycled thermoplastics and adhesive resins. They give the appearance of wood with all the longevity of plastic so they will not rot or require varnishing or painting.

Advantages of gateways

• Delineates the extents of the village and highlights a change of speed limit
• Relatively cheap to install
• Gates come in different sizes to suit most locations

Disadvantages of gateways

• Not as effective as a system of vertical treatments
• Any speed reducing effect could be localised to the village boundary area, for the reduction to be maintained additional measures through the village will be required
• The benefit can reduce over time

Considerations

• These gate features will become the parish / town council’s asset and Cambridgeshire County Council will not maintain or replace them.
• Sizes of gates will be restricted by the width available in the verge.
• A Road Safety Audit will only be required if carriageway widths need to change (for example if the road needs to be narrowed)

Cost of installation

• £4000 for one gateway
• £7000 for two gateways
• £9000 for four gateways.

The gateway cost is based on the supply and installation of 0.95m wide Glasdon Gates in a grass verge, installed under two-way lights.

Effective use of road markings can contribute positively to reducing vehicle speeds. There are many different types of roadmarking that can be used. Some types may incorporate different coloured surfacing to countdown to a speed limit or highlight a particular section of the road.

Roadmarking options available

There are a variety of roadmarking options available below.

Coloured surfacing:

• This can be installed in various locations, to highlight a crossing point, as a 3, 2, 1 countdown to a speed limit, or within central hatching as shown in the picture.
• Colours available include red, beige, and grey.
• It is best applied to a road surface in good repair, so patching work may be required in advance to make good any underlying issues.

Hatching:

• Generally introduced to narrow available running lanes to a narrower consistent width, either by installing central or kerbside hatching.
• In most cases, new road studs will have to be installed along with any hatching which can add to the cost of the work.

Speed roundels or SLOW markings:

• Speed roundels are used to reinforce existing 50, 40, 30 or 20mph speed limits where repeater signs have been mounted on posts or lamp columns within the area.
• SLOW type markings are used alongside warning signs to provide a visual prompt to drivers on the road in conjunction with the sign.

Dragons Teeth:

• Are installed on the approach to a settlement, in advance of the posted speed limit to draw attention to the fact the driver is entering a built-up area.
• They visually narrow the road and are installed in pairs up to a maximum of 15.

Cost of installation

• Coloured surfacing - £7500 for 100m2 of cold applied red surfacing.
• Hatching – £5000 for 500 linear metres of hatching, not including any new road studs.
• Speed roundels or SLOW markings - £2400 for 10no speed roundels or SLOW markings.
• Dragons Teeth - £2000 for a pair of markings.

The costs mentioned above are based on installation under two-way lights as part of a series of markings rather than in isolation. No provision has been made for delivering the work under a road closure, repairing the underlying surface or removal of any existing roadmarkings in advance.

This traffic sign with flashing amber LED beacons and advisory 20mph limit draws attention and ensures drivers are made aware of potential hazards.

This measure is designed to highlight school zones and inform road users of a reduced speed limit at times when parents and children are in the area.

Effectiveness

An excellent solution for drawing highway users’ attention to the fact they are near a school and vulnerable road users may be nearby or crossing the road. This is a solution which is used widely across the county.

Advantages of school flashing lights

• Relatively cheap.

• Nationally recognised and understood.
• No discomfort experienced by any highway user.
• Energy efficient due to being solar powered.

Disadvantages of school flashing lights

• Effectiveness can be diminished if nearby overhanging vegetation is not regularly cut back as part of a regular maintenance regime.
• Speed limit is advisory and not enforceable.
• Units need to be located in areas where they can get adequate light to operate effectively.

Cost of installation

• Solar powered LED flashing sign and post - £8500 per pair.

The costs mentioned above are based on installation under basic traffic management during restricted hours working. No provision has been made for delivering the work under positive traffic management, cutting back existing vegetation, or installing any additional roadmarkings.