Speed bump

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Speed bump made of asphalt
Speed bump made of rubber
Speed bump and warning signs

A speed bump (also known as a sleeping policeman in Jamaica, a kipping cop; in British English a speed hump, road hump (not to be confused with the wider speed hump), speed breaker; in New Zealand English a judder bar; in Hiberno-English a ramp) is a speed-reducing feature of road design to slow traffic or reduce through traffic, via vertical deflection. A speed bump is a bump in a roadway with heights typically ranging between 3 and 4 inches (7.6 and 10 cm). The depth of speed bumps is typically less than or near to 1 foot (30 cm); contrasting with the wider speed humps which are typically 10 to 14 feet (3.0 to 4.3 m) in depth.[1][2]

Speed bumps can be made of recycled plastic, metal, asphalt or rubber. Speed bumps of various sizes can be placed on a road, from using two four foot or six foot devices on it with a space on either side for avoiding the bump on one side of the car, or connected across the entire road surface.

The use of speed bumps is widespread around the world, and they are most commonly found where vehicle speeds are statutorily mandated to be low, usually 40 km/h (25 mph), or 8 to 16 km/h (5 to 10 mph) in car parks.[citation needed] Although speed bumps are very effective in keeping vehicle speed down, their use is sometimes controversial as they can cause noise and possibly vehicle damage if taken at too great a speed.[citation needed] Poorly designed speed bumps often found in private car parks (too tall, too sharp an angle for the expected speed) can be hard to negotiate in vehicles with low ground clearance, such as sports cars, even at very slow speeds.[citation needed] Speed bumps can also pose serious hazards to motorcyclists and bicyclists if not easily noticed, though in some cases a small cut in the bump allows those vehicles to pass through without impedance. Speed bumps cost between $50-200 though they do have to be replaced after wear.[3]



On June 7, 1906, The New York Times reported on an early implementation of what might be considered speed bumps in the U.S. town of Chatham, New Jersey, which planned to raise its crosswalks five inches above the road level: "This scheme of stopping automobile speeding has been discussed by different municipalities, but Chatham is the first place to put it in practice".[4] The average automobile's top speed at the time was around 30 mph.

Arthur Holly Compton was a physicist and winner of the Nobel Prize in physics in 1927 for his discoveries contradicting the then-common belief in the electromagnetic theory. He is commonly known for his work in the Compton Effect with X-ray theories. He invented the speed bump in 1953. Compton began designs on the speed bump after noticing the speed at which motorists passed Brookings Hall at Washington University in St. Louis, Missouri, where he was a chancellor [5].

According to a publication by the Institute of Transportation Engineers, the first speed bump in Europe was built in 1970 in the city of Delft in the Netherlands.[6]

In the UK

In the United Kingdom, vertical deflection in highways for the purpose of traffic calming typically takes one of the following forms:

The Department for Transport defines the regulations for the design and use of road humps.[7]


After complaints from Derby residents, 146 speed bumps were removed from streets at a cost of £460,000. Similar incidents have been reported elsewhere in the UK.[8]

UK news sources reported a cyclist being killed in a crash while attempting to avoid a speed bump.[9]

Speed bumps in some areas have been removed after protests by local residents. Such protests cite the lack of any consultation as one factor.[10]


Local authorities have cited disadvantages to speed bumps:

Other sources argue that speed bumps:

In 2003, the chairman of the London Ambulance Service, Sigurd Reinton was reported as claiming that delay due to speed bumps was responsible for up to 500 avoidable deaths from cardiac arrest each year. He later denied the statement.[14]

In Sweden, an evaluation of spinal stress in bus drivers against ISO 2631-5 required on health grounds[15]:

A potential may exist for liability or at least a law suit when a driver damages his car by going too fast over speed bumps.[16]

Dynamic speed bumps

Dynamic speed bumps differ from conventional speed bumps in that they only activate if a vehicle is traveling above a certain speed. Vehicles traveling below this speed will not experience the discomfort of a conventional speed bump. Dynamic speed bumps may allow the passage of emergency vehicles at higher speeds.

In one design, a rubber housing is fitted with a pressure valve which determines the speed of a vehicle. If the vehicle is traveling below the set speed the valve opens allowing the bump to deflate as the vehicle drives over it, but remains closed if the vehicle is traveling too fast. The valve can also be set to allow heavy vehicles, such as fire trucks, ambulances, and buses to cross at higher speeds.[17][18]

See also


  1. ^ ITE. "Traffic Calming Measures". Institute of Transportation Engineers. http://www.ite.org/traffic/hump.htm. 
  2. ^ TrafficCalming.org. "Speed Humps (Road Humps, Undulations)". Fehr & Peers. http://trafficcalming.org/speedhumps.html. 
  3. ^ "Catalog: Speed Bumps & Humps". Speed Bumps and Humps. http://www.speedbumpsandhumps.com/. Retrieved 29 March 2012. 
  4. ^ "Democratic Rate Plan Favored by Roosevelt [and other news]". New York Times. 1906-03-07. p. 3. 
  5. ^ "Original Traffic control sketch made by Compton in 1953". Washington University Libreries. http://library.wustl.edu/units/spec/archives/facts/images/traffic_control_sketch_1953.pdf. 
  6. ^ Klaus Schlabbach. "Traffic Calming in Europe". Institute of Transportation Engineers. http://www.ite.org/traffic/documents/JGA97A38.pdf. 
  7. ^ "Highways (Road Humps) Regulations 1999 (replacing the 1996 regulations)". UK Department of Transport. http://www.opsi.gov.uk/si/si1999/uksi_19991025_en.pdf. 
  8. ^ "Bumps: Britain gets the hump". London: The Times. October 19, 2003. http://driving.timesonline.co.uk/tol/life_and_style/driving/article994719.ece. Retrieved May 23, 2010. 
  9. ^ "Crash victim's family may file civil action". Strathspey & Badenoch Herald. http://www.strathspey-herald.co.uk/news/fullstory.php/aid/2691/Crash_victim_s_family_may_file_civil_action.html. 
  10. ^ "Speed humps dumped after protest". Auto Express. http://www.autoexpress.co.uk/news/autoexpressnews/67775/speed_humps_dumped_after_protest.html. 
  11. ^ "Speed Hump Fact Sheet". City of Modesto. http://www.modestogov.com/pwd/traffic/pdf/speedhump.pdf. 
  12. ^ "Speed Limits and Reduction: Speed Humps". Eastleigh Borough Council. http://www.eastleigh.gov.uk/ebc-3053#humps. [dead link]
  13. ^ "Like it or lump it: Is the speed hump here to stay?". BBC. July 22, 2003. http://news.bbc.co.uk/2/hi/uk_news/magazine/3084331.stm. Retrieved January 4, 2010. 
  14. ^ "Transport Committee Minutes 11/12/2003". London Assembly. http://www.london.gov.uk/moderngov/CeListDocuments.aspx?CommitteeId=173&MeetingId=3967&DF=11%2f12%2f2003&Ver=2. 
  15. ^ Dr Anders Brandt & MSc Johan Granlund, Swedish Road Administration (2008). "Bus Drivers’ Exposure To Mechanical Shocks Due To Speed Bumps". Society for Experimental Mechanics, IMAC XXVI Conference and Exposition on Structural Dynamics. http://www.dynamicmeasurementsolutions.com/Articles/imacXXVI230__BRA.pdf. Retrieved June 2, 2010. 
  16. ^ "Smart' Stopping Speeders in the Community". Hindman Sanchez. http://www.hindmansanchez.com/docs/stopping_speeders_in_the_community.pdf. 
  17. ^ "Smart speed bumps reward safe drivers". New Scientist. http://www.newscientist.com/article.ns?id=dn1178. 
  18. ^ English, Shirley (November 11, 2005). "Smart' road hump will smooth the way for safe drivers". London: The Times. http://www.timesonline.co.uk/article/0,,2-1867157,00.html. Retrieved May 23, 2010. 

External links