Star.pngStar.pngStar grey.pngStar grey.pngStar grey.png

Speed bump

From Roader's Digest: The SABRE Wiki
Jump to navigation Jump to search
Speed bump
Twmpath arafu
Uchtóg mhoillithe
Park Road speed bumps, Stonehouse - Geograph - 4764713.jpg
Speed bumps in Stonehouse, Gloucestershire
Cameraicon.png Pictures related to Speed bump
View gallery (6)

The term speed bump, hump, or (in Ireland especially) ramp is used to cover a range of speed-reduction measures installed on our roads. Also called speed cushions or sleeping policemen, they have generated a lot of discussion in the last couple of decades, but seem to be here to stay as a relatively cheap method of slowing traffic down.

There are a number of designs in use across the country, but they can generally be categorised as one of the following:

Full-width speed bump

This sees a raised section of road spanning the full width of the carriageway, albeit sometimes with a narrow break against either kerb. This break serves the dual purpose of allowing cyclists to avoid the bump and also maintaining the run of the gutter for drainage purposes. When the road is unkerbed, however, the bump is normally the full width of the road.

The bump itself is often made of tarmac, laid in a roll on the surface of the road. There are various design standards for different types of road, detailing maximum height, width, and angles. However, as this simple type of speed bump is also popular on private roads leading to holiday parks, tourist attractions and so on, these design standards are not always met. The bumps can also be built out of other materials, notably brick, and these usually include a flat top, unlike the simple tarmac versions.

Part-width speed bumps

A development of the speed bump is the speed cushion, a small raised, squarish speed bump placed centrally in each lane. These bumps are designed to be narrow enough not to impede larger vehicles, such as buses, yet too wide to be entirely straddled by cars with their narrower track. However, in practice, modern cars are not that much narrower than small vans, which are used as mini buses and ambulances (amongst other things): the vehicles that the bumps do not want to impede! As a result, many cars are also able to straddle the bumps. Additionally, since many are installed on quiet suburban roads with on-street parking, the bumps can get obscured by parked vehicles, leading to all vehicles being impeded by the need to straddle the central gap, rather than one of the bumps.

When first introduced, the bumps themselves were often constructed from brick, with slopes to all four faces. More recently they have been constructed from small patches of contrasting-coloured tarmac or pre-formed rubber units. In all cases, painted white triangles on the slopes warn motorists of their presence. As noted above, the are placed centrally in each carriageway, so that there is a gap between the bump and the kerb, and a wider gap in the centre of the road. When the road is wide, they are normally joined by build-outs from the kerb, artificially narrowing the road at the location. They can also be used, in conjunction with a build-out, to narrow a generally two-way road to a single carriageway to further slow traffic. In a few rare locations, they are placed 3-abreast, with the third one straddling the central line, forcing traffic to the kerbs if it wishes to straddle the bump.

Raised junctions

Raised junctions, also called speed tables, are used to slow traffic at junctions. Normally constructed of brick, or with brick ramps leading to a raised tarred area, they span the entire junction area, including all approaches. They are most commonly used in the UK at junctions in new housing estates, but have also been retro-fitted to other junctions. An early use of this type of speed bump seems to have been in the High Street in Burnham-on-Sea in Somerset, where each of the junctions had a speed table installed, along with a one -ay system as a half-way house to full pedestrianisation.

Raised crossings

Also classified as speed tables, raised crossings are nevertheless a different type of speed bump. Here the top of the table area is roughly the same length as the normal wheelbase of a long car or short van, or at most when on a bus route, the wheelbase of the bus. This minimises the risk of grounding. The top is generally painted with the zebra crossing lines, with the zig-zags starting at the base of the ramps. Again, the table itself can be constructed just from brick (creating a red and white 'zebra'!) or from brick ramps with a tarred top.

Links - England and Wales

  • The Road Humps (Secretary of State) (Inquiries Procedure) Rules 1986 - These Rules regulate the procedure to be followed in connection with local inquiries caused by the Secretary of State for Transport to be held under section 90C(4) of the Highways Act 1980 in relation to proposals to construct road humps under section 90A or 90B of that Act.
  • The Highways (Road Humps) (Amendment) Regulations 1990 - These Regulations amend the Highways (Road Humps) Regulations 1990 (a) so that where there is a series of humps the application of the requirements specified in regulation 4(4) of those regulations is restricted to the first in the series of humps, and (b) to obviate a minor drafting inconsistency. - Northern Ireland

  • The Road Humps (Amendment) Regulations (Northern Ireland) 2007 - These Regulations amend the Road Humps Regulations (Northern Ireland) 1999 by removing the references to the “Zebra” Pedestrian Crossings Regulations (Northern Ireland) 1974 and the (Pelican) Pedestrian Crossings Regulations (Northern Ireland) 1989 and replacing them with references to The Zebra, Pelican and Puffin Pedestrian Crossings Regulations (Northern Ireland) 2006. - Scotland

  • The Road Humps (Scotland) Regulations 1998 - These Regulations revoke the Road Humps (Scotland) Regulations 1990 and replace them with new provisions, as a result of which the roads authority have more freedom to design and install road humps.

Department for Transport

Speed bump
Related Pictures
View gallery (6)
Park Road speed bumps, Stonehouse - Geograph - 4764713.jpgWhitworth Road N1 sign.jpgR102 Tolka Valley Road.jpgKilmainham R839.jpgR132 Frank Flood Bridge.jpg
Road Basics
Physical layoutSingle track • Single carriageway • Dual carriageway • High Quality Dual Carriageway • Road Widths • Urban Streets • Abandoned Road
Legal typesAll-purpose Road • Special Road • Motorway • Trunk road • Principal road • Classified Numbered road • Classified Unnumbered Road • Unclassified road • Primary Route • Non Primary Route • Right of Way • Unadopted road
Road numbers1922 Road Lists • Classification • Defunct road • Euroroutes • MoT Maps • National Cycle Network • Numbering principles • Numbering anomalies • Disputed Numbers • Recycled number • Unallocated numbers • Fictional Road Numbers • Junction numbers • Essential Traffic Routes • Street Names
Road FeaturesArterial Road • Automatic Bollard • Balancing Pond • Belisha Beacon • Bott's Dots • Bypass • Cannon • Cats' Eyes • Cattle Grid • CD Lanes • Central Reservation • Chopsticks • Crash Barrier • Cuttings and Embankments • Cycle Lane • Emergency Phone • Escape lane • Expressway • Fingerpost • Flare • Ford • Gore • Green Bridge • Green Wave • Hairpin bend • Hard shoulder • Island • Junction • Layby • Level Crossing • Local Access Road • Managed Motorways • Milestone • Multi Lane Drop • Multiplex • No-Car Lane • Nose • Oxbow Road • Parapet • Petrol station • Play Street • Raised Pavement Markers • Ramp Metering • Retaining Wall • Road Studs • Roadside Art • Roadside Quarry • Roadworks • Secret motorway • Service Area • Signage • Smart Motorway • Snow pole • Speed Limit • Spur • Street Lighting • Surface Dressing • Temporary terminus • Throughpass • Tidal Flow • Tiger tail • Toll booth • Traffic cone • Traffic Signals • Tunnel • Vehicle Recovery • Walking and Cycling Friendly Road • Weaving • Wig-Wag Signals • Winter Maintenance • Zip merge
Traffic CalmingBuild-Outs • Chicane • Dragon's Teeth • Home Zone • Low Traffic Neighbourhood • Pinch Point • Quiet Lane • Rumble strips • Safety Cameras • Sleeping Policeman • Speed bump
Public Transport FeaturesBus Lane • Bus stop • Guided Busway • Park and Ride • Tramway • Trolleybus System
Other termsAnderson report • Guildford Rules • Highway Authority • Highway Code • Model Traffic Area • Motorway alphabet • Pre-Worboys • Primary Destinations • Roads by 10 • Transport alphabet • Worboys report

SABRE - The Society for All British and Irish Road Enthusiasts
Discuss - Digest - Discover - Help