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

observational studies on how the degree of surface irregularity impacts vehicle speed anddirection could be useful to assess crash risk with similar road conditions [11].Mechanical problems, in particular tyre bursts, were identified as important causes of fatalcrashes in both settings. Tyre bursts were previously identified as an important vehicle factorinvolved in crashes in LMICs [145]. In most LMICs, car owners prefer using used tyres dueto financial constraints [50]. Previous research has clearly shown that these countries do nothave an effective vehicle inspection system [19, 92]. Irregular road surface conditions oninterurban roads may facilitate frequent tyre burst in LMICs [11]. The relative contribution oftyre problems in crashes indicated that realistic inspection system on interurban road sectionsin LMICs, keeping in mind that car owner might not be able to afford the correspondingmaintenance costs [50]. Road surface improvement may help reduce crashes attributed to tyreproblems in these countries.Traffic demands on the road sector and consistently augmenting in LMICs. Highway traffic isexpected to triple in Pakistan over a period from 2005 to 2015 [81]. The reconstruction andupgrading of highways will certainly increase in these countries. The study on HWZ safety inPakistan, for the first time showed a significantly high traffic crash and fatality burden due tosuch conditions. Guidelines for work zone management exist but so far no mechanism forHWZ design, performance, and enforcement evaluation has been defined or implemented inPakistan [146]. Indeed, there is a need to improve institutional capacity, as well as inspectionmechanisms, so that road agencies could be accountable for ensuring HWZ safety [81, 99,146]. Further, it was observed that lengthy work zones lasted for over 10 months. Thus,efforts are required to reduce HWZ duration to impact crash risks [146].Moreover, one of two HWZ crashes occurred between opposite-direction vehicles; the likelyexplanation was the high volume un-separated traffic conditions and hazardous overtaking.This points out the need to carefully plan and execute the safe flow of traffic duringmaintenance works [147]. Enforcing harsher penalties for overtaking, providing alternatelanes, and traffic separation may be some useful measures to decrease hazardous situationsleading to HWZs crashes in Pakistan [146].Our study showed that pedestrians were significantly involved in HWZ crashes. Sudden entryonto the highway was reported as the major cause of such crashes. Similarly, wet surfacesincreased the risk of HWZ crashes. Such involvements, although less important, were foundin HWZ crashes elsewhere [100]. Human judgement error is indeed one of the principal factoridentified in HWZ crashes [100, 101]. These results indicated that provision of advancewarning area, clear zones to enhance visibility, road markings, and hazard signage in the workarea can be useful interventions to reduce HWZ crashes in Pakistan [94, 146].Adverse weather conditions were involved in a significant proportion of interurban roadcrashes in Cameroon and Pakistan. We observed that there were no specific speed-restrictionsimposed for such conditions on both road sections. Hazard perception for rainy conditionswas lower for high-risk crash sites compared to low-risk sites. These results point out the needfor measures that would help drivers better identify hazards in such conditions at high-risksites. Specific measures, such as all-weather pavement markings, reduced speed limits, andsurface improvements may help reduce such crashes in LMICs [99].The hazard perception study showed that drivers were able to identify only half of high-risksites. A reciprocal relationship of road and traffic hazard perception with reported speed wasobserved. The finding that hazard perception of high-risk sites was significantly differentfrom that of low-risk sites for some of the site factors may have implications for road safety.Hazard perception of high-risk crash sites, for instance with hazard signs, was significantly60