VEHICLE STRUCTURE DESIGNS AND MATERIALS ON SCHOOL BUS BODY CRASHWORTHINESS: A CASE OF VEHICLE BODY BUILDING INDUSTRY IN NAIROBI COUNTY, KENYA.

Abstract

Thousands of vehicles are involved in vehicle collisions or crashes every year in Kenya, resulting in fatal accidents and severe injuries to passengers. There is growing concern among the stakeholders that the design of bus vehicle structures and the levels of crashworthiness are quite alarming. According to experts, school bus vehicle structures and minibuses involved in accidents indicate that the design is substandard and therefore rendering pupils/students more vulnerable to fatalities and serious injuries. Even though vehicle crashworthiness in developed countries has been documented, there is limited research done in Kenya in this specific area. This study attempted to fill the gap by focusing on school bus vehicle structure crashworthiness. The purpose of this study was to establish the effect of vehicle structure designs and materials on bus crashworthiness among body industry players in Nairobi City County. The specific objectives were to determine; the influence of locally designed bus vehicle structure, competency skills, engineering materials, equipment, welding technology, vehicle structure inspection tests and customer needs on crashworthiness of school bus. This study adopted Axiomatic theory, Mathematical Framework theory and Taguchi design theory. The pragmatic philosophy informed the study. The explanatory research design was used. The target population was 1500 respondents from bus body building firms and government regulatory institutions. The sample size was 315 respondents. Questionnaires, interview schedules and observation were the data collection instruments. Supervisors served as expert judgment to establish validity of the instruments. Cronbach’s Alpha Coefficient of >0.7 was used to determine the reliability of the research instrument. The data collected was analyzed using descriptive and inferential analysis with the aid of SPSS V22 software. The multiple regression model, the coefficient of determination (R squared) of .744 showing that 74.4% of the variation in crashworthiness of a bus can be explained by vehicle structures designs and materials. There was a significant relationship between locally designed bus (β1= 0.089), competency skills (β2=0.429) engineering materials (β3= - 0.725), equipment and tools (β4=0.127), welding technology (β5 = 0.575) and inspection test (β6 = 0.321) and customer needs (β7=0.094) crashworthiness of a bus. The engineering materials had a negative and significant influence on crashworthiness of a bus. The equipment, locally designed bus, competency skills, welding technology, vehicle inspection tests and customer needs had a positive significant influence on crashworthiness of a school bus. However the engineering materials used in the manufacture of school buses does not guarantee bus body crashworthiness. The ministry of industrialization should provide incentives to the school bus manufacturing company to locally build school buses that have a lower failure rate. The management of school bus manufacturing companies should periodically send their employees to refresher workshops for competence skills upgrades. This study will help improve school bus body construction and materials thereby enhancing school bus body crashworthiness hence ultimately increasing student survival rates in the event of a school bus accident.