Safety evaluation of right-turn smart channels using automated traffic conflict analysis

Large-scale automated proactive road safety analysis using video data

“…While traffic event conversion factors have been developed and used in the past (Hydén, 1987;Svensson and Hydén, 2006), transferability of validated conversion factors has been cited as problematic (Mohamed and Saunier, 2013). Indeed, while the shape of probability distributions of TTC has generally been characterized as Gamma-like in the literature Autey et al, 2012), variations or compound effects can be found, particularly when traffic streams become mixed . One recent approach proposed a shifted gamma-generalized Pareto distribution model (Zheng et al, 2014).…”

“…Currently, there is a lack of consensus in the literature on how to interpret continuous measures in terms of safety besides the event-based (Hydén, 1987;Svensson and Hydén, 2006) or safety continuum (Zheng et al, 2014) paradigms. One qualitative approach used in the literature has been to compare shifts in the probability distributions of these indicators when the magnitude of impact of individual indicators has no bearing on the overall direction of shift of safety risk Autey et al, 2012;St-Aubin et al, 2013). For example, as illustrated in Fig.…”

Safety evaluation of signalized intersections with left-turn waiting area in China

“…Although it could be greatly desirable and beneficial to conduct the safety analysis on the basis of traffic crash data, there are three critical issues associated with the existing crash database in China: (1) the crash data are heavily underreported, e.g., the property damage only data are typically not included and investigated by the police (Cheng, 2004;Fei et al, 2006); (2) the officially published crash counts are seriously biased due to the political concerns (Fei et al, 2006); and (3) the design layout of LWA at the signalized intersections is relatively new as opposed to the conventional intersections (and currently available only in the capital cities of China) and thus the number of crashes occurring at intersections as such is limited. Also, the historical research works (Gettman and Head, 2003;Oh et al, 2010;Autey et al, 2012;Shahdah et al, 2014) have indicated that the development of safety evaluation based upon the traffic conflict technique can well reflect the safety situation. Comparatively, traffic conflict data are easier to collect and measure as opposed to the crash events (due to the crash characteristics of randomness and rarity) at the intersections with LWA.…”

Safety evaluation of unconventional outside left-turn lane using automated traffic conflict techniques

“…To further evaluate the conflict severity, the minimum TTC of each event can be mapped to a severity index using equation (1) (Saunier et al 2010;Autey et al 2012).…”