Editing Speed bump (section)

==Speed bumps==
[[File:Speed bump (asphalt).jpg|thumb|right|Speed bump made of [[Asphalt concrete|asphalt]]]]
[[File:Ležeći policajac 016.jpg|thumb|right|Speed bump made of [[rubber]]]]
A speed bump is also known as a ''sleeping policeman'' in [[British English]], [[Maltese English]] and [[Caribbean English]], a ''judder bar'' in [[New Zealand English]], and a ''lying-down policeman'' in [[Colombia]], [[Dominican Republic]], [[Hungary]], [[Croatia]], [[Serbia]], [[Estonia]], [[Lithuania]], [[Slovenia]], [[Bulgaria]] and [[Russia]]. A speed bump is a bump in a roadway with heights typically ranging between {{convert|3|and|4|in|cm|0|order=flip}}. The traverse distance of a speed bump is typically less than or near to {{cvt|1|ft|m|1|order=flip}}; contrasting with the wider speed humps, which typically have a traverse distance of {{cvt|10|to|14|ft|m|1|order=flip}}.<ref>{{cite web |author = ITE |title = Traffic Calming Measures |url = http://www.ite.org/traffic/hump.asp |publisher = Institute of Transportation Engineers |access-date = 2014-09-09 |archive-url = https://web.archive.org/web/20170729064350/http://www.ite.org/traffic/hump.asp |archive-date = 2017-07-29 |url-status = dead}}</ref><ref name="trafficcalming.org speedhumps">{{cite web |title=Speed Humps (Road Humps, Undulations) |url=http://www.trafficcalming.org/speedhumps.html |archive-url=https://web.archive.org/web/20081209053906/http://www.trafficcalming.org/speedhumps.html |url-status=dead |archive-date=2008-12-09 |publisher=Fehr & Peers }}</ref>

Speed bumps are used in parking lots and on small-neighborhood roads where space and cost are limited. They are being replaced by Speed Humps (discussed in this Wikipedia section) in higher-traffic areas where speed bumps would be ineffective because bumps are mere blips to law-breaking speeders, while law-abiding drivers must slow to far below the speed limit to avoid large vehicle accelerations and displacements. These are the counter-productive results produced by unavoidable dynamic vehicle response. (See https://lindberglce.com/tech/Worst_Roads.PDF).

Because of these counter-productive responses, speed bumps traversals of at least 2 m (about 5 ft.) with smooth approach and exit should be used wherever possible.

Speed bumps vary in length, but it is typical to leave space between the bump and either edge of an enclosed road (i.e. with curbs and gutters) to allow for drainage. Spaces on either side may also allow more expedient passage for emergency vehicles, though effectiveness will depend on the type of vehicle and specific road design.

===Disadvantages===
[[Local authority|Local authorities]] have cited disadvantages to speed bumps:
*The city of [[Modesto, California|Modesto]] in California, produced a [[fact sheet]] which contains the following disadvantages:<ref>{{cite web|title=Speed Hump Fact Sheet |url=http://www.modestogov.com/ced/pdf/traffic/speedhump.pdf |archive-url=https://web.archive.org/web/20140327051147/http://www.modestogov.com/ced/pdf/traffic/speedhump.pdf |url-status=dead |archive-date=2014-03-27 |publisher=City of Modesto |access-date=2014-03-14 }}</ref>
** Slow response time of emergency vehicles;
** May divert traffic to parallel residential streets; and
** Possible increase in noise and pollution for residents living immediately adjacent to the speed bumps.
* The English town of [[Eastleigh]] states the following as disadvantages:<ref>{{cite web|title=Speed Limits and Reduction: Speed Humps |url=http://www.eastleigh.gov.uk/ebc-3053#humps |publisher=Eastleigh Borough Council |url-status=dead |archive-url=https://web.archive.org/web/20060927075215/http://www.eastleigh.gov.uk/ebc-3053 |archive-date=September 27, 2006 }}</ref>
** Can cause damage to some vehicles;
** Can increase traffic noise, especially when [[large goods vehicle]]s pass by;
** Required signs, street lighting and white lines may be visually intrusive;
** Can cause discomfort for drivers and passengers;
** Can cause problems for emergency services and buses.

Other sources argue that speed bumps:
* Distract drivers from other hazards such as children
* Increase pollution as traffic travels in a lower gear using significantly more fuel per mile;
* Are a compromise for more active enforcement;
* Increase noise by creating tire-to-bump thumping and increasing the amount of engine-revving;
* Cause spinal damage<ref>{{cite news|url=http://news.bbc.co.uk/2/hi/uk_news/magazine/3084331.stm|publisher=BBC|title=Like it or lump it: Is the speed hump here to stay?| date=July 22, 2003 | access-date=January 4, 2010}}</ref> and aggravate chronic backache.

In 2003, the chairman of the London Ambulance Service, Sigurd Reinton claimed that delays caused by speed bumps were responsible for up to 500 avoidable deaths from cardiac arrest each year. He later denied the statement.<ref>{{cite web|title=Transport Committee Minutes 11/12/2003|date = 11 December 2003|url=http://www.london.gov.uk/moderngov/CeListDocuments.aspx?CommitteeId=173&MeetingId=3967&DF=11%2f12%2f2003&Ver=2|publisher=London Assembly|access-date=2014-03-14}}</ref>

In Sweden, an evaluation of spinal stress in bus drivers against ISO 2631-5 required on health grounds that:<ref>{{cite web|url=http://www.dynamicmeasurementsolutions.com/Articles/imacXXVI230__BRA.pdf|publisher=Society for Experimental Mechanics, IMAC XXVI Conference and Exposition on Structural Dynamics|title=Bus Drivers' Exposure To Mechanical Shocks Due To Speed Bumps|author=Dr Anders Brandt & MSc Johan Granlund, Swedish Road Administration|year=2008|access-date=June 2, 2010|url-status=dead|archive-url=https://web.archive.org/web/20110710160659/http://www.dynamicmeasurementsolutions.com/Articles/imacXXVI230__BRA.pdf|archive-date=July 10, 2011}}</ref>
* bus drivers avoid certain streets until the humps were modified; and
* the maximum acceptable speed be reduced to {{convert|10|km/h|mph m/s}} on one street for drivers encountering 150 humps in a day.

Speed bumps can also have adverse environmental impact. A study found that in one north London street with a speed limit of {{convert|20|mph|km/h m/s}} and fitted with road humps, a petrol driven car produced 64 per cent more nitrogen dioxide (NO<sub>2</sub>) than in a similar {{convert|20|mph|km/h m/s}} street fitted with road cushions. It also produced 47 per cent more particulate matter (PM) and nearly 60 per cent more carbon monoxide (CO) emissions.<ref>{{cite news|url=https://www.telegraph.co.uk/news/2016/12/01/speed-bumps-could-removed-cut-traffic-pollution-save-lives/|publisher=Telegraph|title=Speed bumps could be removed to cut traffic pollution and save lives|date=1 December 2016|access-date=23 April 2021}}</ref> Another study estimated that, for a private automobile, the increase in fuel consumption due a pass over a speed bump is responsible for fuel waste of 10ml.<ref>{{cite journal |last1=Jazcilevich |first1=Aron |last2=Mares Vázquez |first2=José María |last3=Ramírez |first3=Pablo López |last4=Péreza |first4=Irma Rosas |title=Economic-environmental analysis of traffic-calming devices |journal=Transportation Research Part D: Transport and Environment |date=May 2015 |volume=36 |pages=86–95 |doi=10.1016/j.trd.2015.02.010 |bibcode=2015TRPD...36...86J |url=https://www.sciencedirect.com/science/article/pii/S136192091500019X |access-date=23 April 2021|url-access=subscription }}</ref> This multiplied with the number of vehicles going over a particular speed bump every day suggests significant annual fuel wastage for a single speed bump.

===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 vehicle]]s at higher speeds.

The [[Actibump]] system, successfully used in Sweden, is based on powered equipment integrated into the road surface, which operates a platform that is lowered a few centimeters when a speeding vehicle approaches. Any vehicle approaching at or under the speed limit will pass on a level road. The system measures the speed of an oncoming vehicle by using radar.<ref>{{cite web|title=Actibump|url=http://www.actibump.com|publisher=Edeva|access-date=2016-12-01}}</ref>

In another design, a rubber housing is fitted with a [[pressure relief valve]] that 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 it remains closed if the vehicle is traveling too fast. The valve can also be set to allow heavy vehicles, such as [[Fire apparatus|fire trucks]], [[ambulance]]s, and [[bus]]es to cross at higher speeds.<ref>{{cite journal|url=https://www.newscientist.com/article.ns?id=dn1178 |journal=New Scientist |title=Smart speed bumps reward safe drivers |url-status=dead |archive-url=https://web.archive.org/web/20070326103037/http://www.newscientist.com/article.ns?id=dn1178 |archive-date=March 26, 2007 }}</ref><ref>{{cite news|url=http://www.timesonline.co.uk/article/0,,2-1867157,00.html |work=The Times |title=Smart' road hump will smooth the way for safe drivers |location=London |first=Shirley |last=English |date=November 11, 2005 |access-date=May 23, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20060113164245/http://www.timesonline.co.uk/article/0%2C%2C2-1867157%2C00.html |archive-date=January 13, 2006 }}</ref>