thèse doctorat de l'université bordeaux 2 - ISPED-Enseignement à ...

perception for high risk site videos with rain was significantly lower than low risk site videoswith same conditions.DISCUSSIONThis study showed that drivers were able to discriminate only half of high-risk sitesfrom their matched low-risk sites. Further analysis showed that certain driver-, road-, andtraffic-related characteristics were associated with a low hazard perception. For instance,participants who drove cars and mini-trucks had overall low hazard perception as compared tothose driving trucks. Similarly, hazard perception of sites with flat and straight road profilewas significantly lower than those without these profiles. Furthermore, high-risk crash sitessituated in built-up area, with lane width ≤ 8 m, and during rainy conditions were perceivedless hazardous than low-risk sites with same features.The study methods were inspired from diagnostic test studies, to assess the accuracyof drivers in differentiating high-risk sites from the low-risk ones (Flahault et al., 2005), andto analyze factors associated with low hazard perception. This study, for instance, showed thathazard perception of high-risk crash sites generally remained low, particularly for those siteswhich were straight and flat. Confronting these findings with the fact, previously shown onYaoundé-Douala road section, that crashes were significantly higher for a road section withflat profile (Bhatti et al.); this study suggested that drivers preferred higher traffic speeds atflat road sites (Afukaar, 2003; Damsere-Derry, Afukaar, Donkor, & Mock, 2008). Suchinformation could be extremely useful for safety experts, and these methods might facilitateprioritizing and providing insights into possible interventions at high-risk sites (Bishai,Asiimwe, Abbas, Hyder, & Bazeyo, 2008).Furthermore, these methods assessed the odds of poor hazard perception of high-riskcompared to low-risk sites with same road features. For instance, the high-risk sites situated inbuilt-up areas were not perceived hazardous compared to low-risk sites with similar roadcharacteristics. Indeed, the incidence of RTCs on interurban road sections is higher in LMICsthan in developed countries (Mohan, 2002). Ribbon development, improper crossingfacilities, higher traffic mix, and absence of service lanes in LMICs could explain this crashrisk in built-up areas (Ross et al., 1991). Our results suggested that implementinginterventions which increase hazard perception might reduce crash risk on such sites (Bhattiet al.).Moreover, narrow lane widths increased road hazard perception and reduced trafficspeed except for high-risk sites. It is likely that drivers were unable to perceive thehazardousness of such sites, because of little road furniture and hazard signage regardingspeed adjustments, a condition frequent in LMICs (Mohan, 2002; Ross et al., 1991). This wasconsistent with the observation that high-risk sites with hazard signs resulted in higher hazardperception levels. This clearly indicated that proper installation and maintenance of such signscould have long-term road safety implications in LMICs (Milleville-Pennel, Hoc, & Jolly,2007).Previous studies have showed that adverse weather conditions significantly increasedinterurban RTC risk in LMIC (Hijar et al., 2000; Majdzadeh, Khalagi, Naraghi, Motevalian,& Eshraghian, 2008). Our results showed that the ability to detect hazardousness of high-risksites could be compromised during such weather conditions. Enforcing low traffic speeds andinstallation of real-time speed indications during such conditions could reduce crash risk onthese roads (Konstantopoulos, Chapman, & Crundall).129