Enforcement avoidance behavior near automated speed enforcement areas in Korean expressways

Evaluation of Section Speed Enforcement System Using Empirical Bayes Approach and Turning Point Analysis

“…It is evident from these observations that, unlike ASES, there were no momentary and abrupt speed reductions along sections with SSES. Furthermore, the 43% reduction in crash occurrence in the sections with SSES is 5.6 times greater than the reduction with ASES, which showed only a 7.6% reduction, as reported in a previous study also performed with data from Korean expressways [3]. It is manifested that SSES has more favorable effects on traffic safety and constant vehicle speed than does conventional ASES.…”

“…SSESs have been introduced to control speeding over roadway stretches and to remedy the enforcement avoidance behavior prevalent for ASES, including momentary slowing only at locations of enforcement [3]. In this study, based on data from nine Korean expressway sections where SSESs had been installed, we evaluate the effectiveness of SSES on reducing vehicle speed and crash occurrence.…”

“…In general, the prediction model is estimated using a negative binomial (NB) regression; the parameters in equation (3) are the estimated outcomes: α is the overdispersion parameter, and P b i is the expected number of crashes estimated from the prediction model. For the crash prediction model, we have used the crash data for four years (2007-2010) and the annual average daily traffic data from 1,128 roadway segments of Korean expressways.…”

“…For the crash prediction model, we have used the crash data for four years (2007-2010) and the annual average daily traffic data from 1,128 roadway segments of Korean expressways. In this study, we adopted the prediction model that was previously specified for the same coverage of Korean expressways in Shim et al [3]. e prediction model is crashes/year � l × exp(0.225 + 1.45 * 10 − 5 * AADT), where l is the length of the section and AADT is the average annual daily traffic for the section.…”

“…is type of enforcement system is installed to reduce traffic speed upstream of certain locations, especially where speeding-related crashes frequently occur. However, the local law often mandates informing drivers of enforcement locations, thereby drivers with that information naturally adjust their speeds to avoid enforcement: drivers tend to slow their speeds when approaching enforcement locations and return to their original speeds shortly after passing the locations [1][2][3]. is enforcement avoidance behavior leads to a criticism of the effectiveness of ASES, in which the system promotes abrupt changes in vehicle speed near enforcement locations, increasing crash risk as a side effect.…”