Speed limits, humps and traffic calming

If you would like a speed limit to be lowered, raised or extended, please contact us. Your request will then be assessed. The police view on a change to a speed limit is important and will be sought. Account should also be taken of the characteristics of the road, such as its alignment, the level of activity alongside the road, the accident record and the degree of severance caused to a community by the speed of vehicles.

In urban areas, speed limits should fit into a rational and easily understood hierarchy if they are to be observed by drivers. Before deciding to change an existing speed limit the Highway Authority must consider all the relevant factors such as:

• expected accident savings
• improvement to the environment
• improvement in amenities
• reduction in public anxiety
• improved facilities for vulnerable road users
• delays to traffic
• costs of implementation
• costs of engineering measures and their maintenance
• costs of enforcement, especially where the speed limit is regarded as unreasonable by drivers

If it is considered that a change in the speed limit is warranted then a new Speed limit Order has to be made. This involves a statutory legal process that takes approximately 9 months to complete.

If you wish to report a vandalised/missing speed limit sign, please contact us on 020 8356 2897.

If the road in question has a system of street lighting on it with no speed limit repeater signs the road is already subject to 30mph and as such the Highway Authority is not permitted to place 30 mph repeater signs on it. The system of street lighting in a built up area should be sufficient evidence of 30 mph limit.

We receive many requests from residents for these to be introduced in their roads to reduce speeds and improve safety.

The Police, Fire Brigade, Ambulance Service and bus companies usually oppose the use of speed control humps. The emergency services object because humps increase their attendance times for emergency calls, and thus risk the lives and property of the people. The Ambulance Service and bus companies object because of the discomfort and possible injury that can be caused to their passengers and the increased wear and tear on vehicles, particularly buses going over speed tables every day.

There are regulations governing the layout of speed control humps. There must be a form of  “slowing feature” – usually formed by a change of priority (traffic entering the system has to turn sharp left or right into the road, or has to give way. Sometimes mini roundabouts are used at the start of a system of humps.

The shape of speed control humps is strictly regulated. They must be between 50mm and 100mm high, at least 2.75m long and extend over the full width of the road, except for a drainage channel at either end. They may have either flat tops or round tops. Many local authorities have adopted the 75mm high hump as a standard. This is because it has been found to reduce traffic to around 22 mph.

The 100 mm high humps reduce speeds to 17 mph on the hump but speeds rise to 35 mph between the humps, causing excessive acceleration, braking and increased pollution. Flat topped humps can be of any length and are often known as “speed tables”. They are sometimes used to reduce the impact on long wheel base vehicles such as buses.

Speed control humps can lead to complaints about increased noise and sometimes increased vibration from traffic. They have however been proved to reduce traffic speed and they have been installed in many locations.

These are a form of speed control hump which are wide enough to allow a wide wheelbase vehicle to pass unhindered. Buses or a fire engines are not affected by them, whereas a smaller wheelbase vehicle, such as a car, would have to have at least one set of wheels on the hump. Thus cars are slowed, whereas other traffic is generally unaffected. These are intended to overcome the objections of the emergency services and bus companies.

They make possible speed reduction measures in roads that would otherwise not have them introduced. If you’d like more information or would like to register a complaint concerning speed humps, please contact us.