An extract on #asayi
Speed limits are set primarily to balance road traffic safety concerns with the effect on travel time and mobility. Speed limits are also sometimes used to reduce consumption of fuel or in response to environmental concerns.
Some speed limit have also been initiated to avoid import too much gas-oil during 1973 oil crisis.
Fuel efficiency sometimes affects speed limit selection. The United States instituted a National Maximum Speed Law of 55 mph (89 km/h) as part of the Emergency Highway Energy Conservation Act in response to the 1973 oil crisis to reduce fuel consumption. According to a report published in 1986 by The Heritage Foundation, a Conservative advocacy group, the law was widely disregarded by motorists and hardly reduced consumption at all. In 2009 The American Trucking Associations called for a 65 mph speed limit and also national fuel economy standards claiming that the lower speed limit was not effective at saving fuel. European studies have claimed that, whereas the effects of specific speed reduction schemes on particulate emissions from trucks are ambiguous, lower maximums speed for trucks consistently result in lower emissions of CO2 and better fuel efficiency.
Speed limits, and their enforcement have been opposed by various groups and for various reasons since their inception. Historically, the AA was formed in 1905, initially to warn members about speed traps.
In more recent times some advocacy groups seek to have certain speed limits as well as other measures removed. For example, automated camera enforcement has been criticised by motoring advocacy groups the Association of British Drivers, the North American National Motorists Association, and the German Auto Club.
Arguments used by those advocating a relaxation of speed limits or their removal include:
A 1994 peer-reviewed paper by Charles A. Lave et al. titled Did the 65 mph Speed Limit Save Lives? stated that evidence that a higher speed limit may be positive on a system wide in the United States by shifting more traffic to these safer roads.
A 1998 report in the Wall Street Journal title 'Highways are safe at any speed' stated that when speed limits are set artificially low, tailgating, weaving and speed variance (the problem of some cars traveling significantly faster than others) make roads less safe.
In 2010, German Auto Club (a major motoring organisation) argued that an autobahn speed limit was unnecessary because numerous countries with a general highway speed limit had worse safety records than Germany, for example Denmark, Belgium, Austria, and the United States.
In 2008, the German Automobile Manufacturer's Association called general limits "patronizing", arguing instead for variable speed limits. The Association also stated that "raising the speed limits in Denmark (in 2004 from 110 km/h to 130 km/h) and Italy (2003 increase on six-lane highways from 130 km/h to 150 km/h) had no negative impact on traffic safety. The number of accidental deaths even declined".
Safe Speed, a UK advocacy organisation campaigns for higher speed limits and to scrap speed cameras on the basis that the benefits were exaggerated and that they may actually increase casualty levels; their ePetition to the UK government in 2007 calling for speed cameras to be scrapped received over 25,000 signatures.