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

MethodsStudy design and settingStudy design was based on a historical cohort study [104, 105]. Highway police crash reportsand traffic statistics for a three-year period (2006-2008) were used to assess the injury risks inHWZs. The study setting was a 196-km long four-lane, separated, section of the Karachi-Halaroad in the province of Sindh, Pakistan (Figure 12). This is one of the most heavily used roadsections, with traffic counts ranging from 16,356 to 24,707 vehicles per day [83]. The NHAPakistan manages maintenance and upgrading operations on this road section. The NHMPhave been enforcing traffic rules on this road section since 2004.Figure 12. Karachi-Hala Road Section, province of Sindh, PakistanChinaBaluchistanIndiaAfghanistanIndiaArabian seaSelected roadOther roadBoundriesCitiesArabian SeaTraffic dataAnnual average daily traffic survey data were collected from NHA headquarters. Thesesurveys are conducted each year to assess traffic counts on different road sections underFederal administration. Locations near toll plazas are selected to assess 24-hour counts byNHA personnel. We extracted information on traffic counts observed between Karachi-Hyderabad (146 km) and Hyderabad-Hala (50 km) sub-sections. Variables included in trafficsurveys were number, type (trucks, buses transporting ≥ 20 passengers, mini-truck, minibus orcoasters transporting < 20 passengers, cars or jeeps, and motorcycles), and direction ofvehicles (North-bound or South-bound) [83].In Pakistan, during maintenance works on separated interurban roads, two or more lanes in agiven direction are completely blocked and traffic, on most occasions, is diverted tooppositely directed lanes (Figure 13). Police and highway authorities facilitate privatecontracting agencies in traffic control during construction periods. Details of HWZ start andend dates and km locations are recorded in their memos. We collected this data from NHAand NHMP regional offices.42