Institute of Transport Economics, Gaustadalléen 21, 0349 Oslo, Norway.
Accid Anal Prev. 2009 Sep;41(5):897-905. doi: 10.1016/j.aap.2008.08.011. Epub 2008 Sep 5.
A meta-analysis has been conducted on the effects of red-light cameras (RLCs) on intersection crashes. The size and direction of results reported from studies included in the meta-analysis are strongly affected by study methodology. The studies that have controlled for most confounding factors yield the least favourable results. Based on these studies, installation of RLCs leads to an overall increase in the number of crashes by about 15%. Rear-end collisions increase by about 40% and right angle collisions, which are the target crashes for RLC, are reduced by about 10%. All effects are, however, non-significant. Meta-regression analysis shows that results are more favourable when there is a lack of control for regression to the mean (RTM). An interaction is found between control for RTM and control for those spillover effects that result from the tendency of RLCs to affect crash levels in nearby intersections without RLC. In studies controlling for RTM, additional control for spillover effects reduces the favourability of results still further. Studies controlling for both RTM and spillover effects tend also to control for more additional factors than other studies. It is likely that the results are affected by additional moderator variables, which could not be investigated in this meta-analysis. RLCs may reduce crashes under some conditions, but on the whole RLCs do not seem to be a successful safety measure.
已经对红光灯（RLC）对交叉口事故的影响进行了荟萃分析。荟萃分析中包含的研究报告的结果的大小和方向受到研究方法的强烈影响。控制了大多数混杂因素的研究得出的结果最不利。根据这些研究，安装 RLC 会导致事故总数增加约 15％。追尾碰撞增加了约 40％，而 RLC 的目标碰撞（直角碰撞）减少了约 10％。但是，所有影响均无统计学意义。元回归分析表明，当缺乏对均值回归（RTM）的控制时，结果更为有利。发现 RTM 的控制与由于 RLC 倾向于影响无 RLC 的附近交叉口的碰撞水平而产生的溢出效应的控制之间存在交互作用。在控制 RTM 的研究中，进一步控制溢出效应会进一步降低结果的有利性。控制 RTM 和溢出效应的研究也倾向于比其他研究控制更多的其他因素。结果可能受到其他无法在此荟萃分析中进行调查的附加调节变量的影响。在某些情况下，RLC 可能会减少碰撞，但总体而言，RLC 似乎不是一项成功的安全措施。
