A comparative analysis of accident modification functions for traffic law enforcement
本文比较了描述交通执法对事故影响的函数，提出用双重差分法结合多元事故预测模型来构建包含执法增减的修正函数，并举例说明，对交通安全研究者有参考价值。
Traffic law enforcement is a road safety measure whose effects on accidents or injuries is best described by means of a function rather than a point estimate. An informative function should comprise both increases and decreases in enforcement. Currently available accident modification functions cannot serve this need. A fruitful approach to developing accident modification functions covering both increases and decreases in enforcement is differences-in-differences estimates based on multivariate accident prediction models. The paper explains how to develop such estimates and illustrates them. The interpretation of the results of empirical studies can be informed by a game-theoretic model of the effects of enforcement, previously published in Accident Analysis and Prevention (Bjørnskau and Elvik 1992, 507-520).