Impact of Mobile Photo Enforcement (MPE): An Analysis of the Duration Between Collisions at Enforced Sites
Creators: Agina, Samaa
Publisher: name: University of Alberta Library
Year: 2022

<p>Road collisions are one of the leading causes of death globally (1), with pedestrians, cyclists, and motorcyclists accounting for more than 50% of road traffic fatalities. Many countries work hard to provide safer roads for all users, especially vulnerable ones, not least because the cost to most countries is approximately 3% of their total domestic product. Vision Zero (VZ) aims to eliminate fatalities and severe injuries from road collisions. There is a need to determine the contributing factors leading to collisions to assess and apply appropriate solutions to accomplish that goal. For instance, speeding is a significant causal factor of road collisions, and an increase in the average speed increases the probability of a crash and its severity. To deter speed violations, Mobile Photo Enforcement (MPE) programs have been used as an effective countermeasure. <br>
    Past research has investigated the effectiveness of MPE in reducing the number of speed violators and providing safer roads. Following that, this thesis’s primary goal is to study the potential impact of the MPE deployment efforts on the duration between two consequent collisions by examining 250, 175, 212, and 219 sites in the City of Edmonton, Canada, in 2019, 2018, 2017, and 2016, respectively. These sites had varying traffic volume levels, roadway categories, and conditions. The research methodology was performed in two main stages, namely, preparing the data for testing and applying a rigorous statistical analysis. The data was obtained from the City of Edmonton’s Safe Mobility Section. Survival analysis was applied to investigate the relationship between the MPE variables and the duration between collisions.<br>
    The KM survival estimates were applied to the classified groups to determine those had higher survivability. The groups were classified into two clusters based on MPE hours, MPE visits, MPE HpVs, and traffic count separately. A graph highlighted those clusters with a higher survival probability and a median survival probability over the study period (one year). Next, log-rank tests were carried out to emphasize and support the results of the KM survival graphs. The log-rank test established whether the two tested groups had the same survivability. <br>
    The outcomes of this analysis further support the positive effect of deployed MPE hours and visits on increasing the duration between consequent collisions, which correspondingly reduced the risk of collision occurrence. The results showed that the ratio between hours and visits (i.e., hours per visit) has the most impact on increasing the duration between collisions and reducing the risk of collision occurrence. The expected reduction in the collision hazard (i.e., collision occurrence) varied between 22% and 52%; the maximum reduction could be expected when the deployment occurs in high traffic volume locations, and the minimum reduction could be expected at &quot;Arterial Only&quot; and &quot;All Sites&quot; together regardless of any classifications. This conclusion is based on the results of the Cox proportional hazard models in 2019, 2018, 2017, and 2016. Moreover, KM graphs showed that the above-average MPE variables groups had a higher survival probability than those below-average. In addition, the log-rank tests confirmed the KM graphs inference.</p>