Total target crashes [crashes during nonpeak periods that are materially affected by camera enforcement] were reduced by an estimated 44 to 54 percent, injury crashes by 28 to 48 percent, and property damage only crashes by 46 to 56 percent during the nine month program period.
(The program was temporarily suspended, then reactivated; future evaluations may elaborate on the results.) Since analyses found low speeding detection rates during peak travel times, the target crashes (speeding-related crashes) were considered to be those that occurred during non-peak flow periods (weekends, holidays, and non-peak weekdays hours).
“Speed cameras have been used in 12 States and the District of Columbia ([IIHS, 2010a]), but not all of these programs may be active at present” (UNC Highway Safety Research Center, 2011, p.
3-12) because local jurisdictions generally contract private firms for the operation of these systems and contract durations vary.
Support appears highest in jurisdictions that have implemented red-light or speed cameras. Australian researchers discussed how Australia and the United Kingdom have dealt with the opponents of and controversies associated with speed cameras and expanded programs at the same time ([Delaney, Diamantopoulou, and Cameron, 2003]; [Delaney, Ward, et al., 2005]). 3-14) Where cases have been brought, state courts have “consistently supported the constitutionality of automated enforcement” (UNC Highway Safety Research Center, 2011, p. Covert, mobile speed camera enforcement programs may provide a more generalized deterrent effect and may have the added benefit that drivers are less likely to know precisely when and where cameras are operating.
However, efforts to institute automated enforcement often are opposed by people who believe that speed or red-light cameras intrude on individual privacy or are an inappropriate extension of law enforcement authority. Drivers may therefore be less likely to adapt to speed cameras by taking alternate routes or speeding up after passing cameras, but data are lacking to confirm this idea ([L. Public acceptance [of speed cameras] may be somewhat harder to gain with more covert forms of enforcement ([FHWA and NHTSA, 2008]).
“Information on States’ laws authorizing or restricting use of automated enforcement is provided by the GHSA ([2014c]) and by IIHS ([2014b])” (UNC Highway Safety Research Center, 2011, p. The best-controlled studies suggest injury crash reductions are likely to be in the range of 20 to 25 percent at conspicuous, fixed camera sites. (2009) study examined effects of a fixed camera enforcement program applied to a 6.5-mile urban freeway section through Scottsdale, Arizona.
Collision outcomes include the number or rate of crashes stratified by severity (property damage only, injury, or fatality).
Crash and injury outcomes were not evaluated in these studies. 3-13) A 2010 update to a 2006 Cochrane systematic review on the effectiveness of speed cameras included an additional nine high-quality studies and maintained the qualitative results from the previous review (C.
Wilson, Willis, Hendrikz, Le Brocque, and Bellamy, 2010).
For example, the Arizona Department of Public Safety allowed a two-year freeway speed-camera program contract to expire in 2010 (city cameras continue to remain in effect).
A compilation of industry listings shows that 92 local governments and authorities had active automated speed cameras as of September 2011, but exact numbers are difficult to obtain because of the lack of federal regulatory oversight (Madsen and Baxandall, 2011).