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Sleeping Policeman, A Love/Hate Relationship with Speed-Bumps |

Seton Speed Bump Evolution - A Technological Timeline of Traffic Calming Measures

What is a Sleeping Policeman?

Black car approaches a black and yellow Seton Speed Bump in a car park

A sleeping policeman is a traffic calming device which is used to reduce speed and lower the risk of accidents. Sleeping Policemen are also known as speed bumps and speed humps and they are often used in private roads such as housing estates, construction sites and schools to restrict speed limits to either 5 mph or 10 mph.

Where do Sleeping Policemen Originate From?

On June 7 1906, Chatham in New Jersey was the first place to implement a speed calming device. Materials such as flagstones and cobbles were used to raise pavements by five inches. In 1953 a sleeping policeman was designed by a physicist named Arthur Holly Compton to slow down traffic outside his University, it was similar to the speed bumps that we use today. Traffic calming measures become increasingly popular around the world and Britain's first sleeping policeman appeared in 1983.

The sleeping policeman name was originated in Britain.However it has many different names in other countries. In New Zealand English they are called a Juddar Bar and in Croatia, Slovenia and Russia they use the term Lying-Down Policeman to describe a speed bump. They may have various names but they are still used as a traffic calming device to make roads safe.

Are There Different Types of Sleeping Policemen?

Large white van drives over a black and yellow Seton Speed Bump in a car park

Speed bumps have developed through time. There are a variety of options which serve the same purpose as a sleeping policemen, however they are suited to different locations.

Speed Humps: A rounded hump that normally covers the entire width of a road. Speed humps are often constructed using materials such as PVC, concrete or tarmac. Humps are commonly used in residential streets to decrease speed in hazardous areas. They also reduce risks to pedestrians and vehicles as speed humps usually restrict speeds to 15 mph - 20 mph.

Speed Cushions: These small rectangular humps are suitable for routes used by emergency vehicles such as ambulances and fire engines. As emergency vehicles have wide axles they can pass over the cushion without having to slow down. Speed cushions can also be used in high risk areas such as outside schools to reduce potential danger.

Speed Tables: A type of speed hump that is usually made from either bricks or recycled textured rubber materials. Speed tables are often used at junctions or pedestrian crossings.

Chicanes: These are artificial bends in the road which force oncoming traffic to slow down as vehicles have to maneuver around the curves.

How do Sleeping Policemen Enhance Road Safety?

Traffic calming devices such as the sleeping policemen have a positive impact as they reduce casualties and death rates caused by speeding.

In 2017 the World Health Organization found that 40-50% of drivers go over speed limits. This has a massive impact as road traffic crashes are the number one cause of death among young people aged between 15-29 years. Sleeping Policemen help reduce risks and save lives.

It is important to make vehicles and pedestrians aware of restricted speed limits and hazardous areas, especially when visibility is low. Use traffic signs to convey clear precise messages where needed.

What are Sleeping Policemen Made From?

Yellow and black PVC Sleeping Policeman with rail

Traditional sleeping policemen are usually made from materials such as rubber or tarmac. New technology has come along and shown that speed bumps made from PVC are much more durable than traditional alternatives. This is why many new speed bumps use robust PVC to raise longevity.

PVC Speed Bumps have many advantages such as:

  • Increased strength
  • High visibility
  • Strong protection against the elements
  • Abrasion resistance
  • Reducing risks
  • Improving health and safety

How do Sleeping Policemen Help the Environment?

On 26 July 2017 the Government's Air Quality Plan for Nitrogen Dioxide was released. Their proposal suggested decreasing the amount of speed bumps to reduce air pollution.

However, Living Streets have found evidence that removing sleeping policemen would have an insufficient effect on reducing air pollution. Instead it would increase the risk of accidents and endanger lives. If a pedestrian was hit by a vehicle at 20 mph they have a 97% chance of survival. As speed increases the chance of staying alive reduces. The Royal Society for the prevention of Accidents have stated using traffic calming devices such as speed humps is the most efficient way to reduce speed.

Guidelines from NICE – the National Institute For Health and Clinical Excellence

We recommend installing our speed bumps in locations such as car parks, schools and construction sites.

Seton Speed Bump - New Innovation

A demonstration of how the Sleeping Policemen are fixed onto the new innovative rail using a range of galvanised bolts

We have created our traffic calming device using a new, innovative design to enhance overall performance. Our exclusive PVC speed bump with rail increases visibility, durability and safety.

The unique rail system has been thoroughly tested and computer simulations have been used to find out if our installation method does increase strength over traditional alternatives.

Case 1: Maximum Stationary Tyre Loading - Stress

  • Results showed that there were higher stress levels on our steel channel fixing which means it provides added support to the PVC bump
  • Stress is transferred to the rails instead of the speed bump

Case 2: Maximum Stationary Tyre Loading - Displacement

Shows how the robust rail system is attached to the inside of a yellow PVC Sleeping Policeman
  • Test results proved that the rail system reduced corner flexing
  • Metal channel also provides vertical support leading to lower overall deformation

Results from Oxford Product Design

Seton Speed Bumps are available in two installation options, with rail and without rail. These can be fixed to either concrete or tarmac surfaces. Our speed bump can also be used as a parking block to make drivers aware of when they need to stop. This would be especially useful for lorries at loading bays. They can also use them to mark out parking bays which will reduce accidents as they stop drivers parking too closely together, or traffic lanes to reduce potential collisions by making sure drivers stay in the correct lane.