Single-vehicle crashes along rural mountainous highways in Malaysia: An application of random parameters negative binomial model.
Mountainous highways generally associate with complex driving environment because of constrained road geometries, limited cross-section elements, inappropriate roadside features, and adverse weather conditions. As a result, single-vehicle (SV) crashes are overrepresented along mountainous roads, particularly in developing countries, but little attention is known about the roadway geometric, traffic and weather factors contributing to these SV crashes. As such, the main objective of the present study is to investigate SV crashes using detailed data obtained from a rigorous site survey and existing databases. The final dataset included a total of 56 variables representing road geometries including horizontal and vertical alignment, traffic characteristics, real-time weather condition, cross-sectional elements, roadside features, and spatial characteristics. To account for structured heterogeneities resulting from multiple observations within a site and other unobserved heterogeneities, the study applied a random parameters negative binomial model. Results suggest that rainfall during the crash is positively associated with SV crashes, but real-time visibility is negatively associated. The presence of a road shoulder, particularly a bitumen shoulder or wider shoulders, along mountainous highways is associated with less SV crashes. While speeding along downgrade slopes increases the likelihood of SV crashes, proper delineation decreases the likelihood. Findings of this study have significant implications for designing safer highways in mountainous areas, particularly in the context of a developing country.
Queensland University of Technology (QUT), Centre for Accident Research and Road Safety-Queensland (CARRS-Q), 130 Victoria Park Road, Kelvin Grove, QLD 4059, Australia; Politeknik Sultan Mizan Zainal Abidin, Jalan Paka, 23000 Dungun, Terengganu, Malaysia. Electronic address: rusdibin.rusli@hdr.qut.edu.au.
Rusdi
R
Rusli
Queensland University of Technology (QUT), Centre for Accident Research and Road Safety-Queensland (CARRS-Q), 130 Victoria Park Road, Kelvin Grove, QLD 4059, Australia; Queensland University of Technology (QUT), Civil Engineering and Built Environment, Science and Engineering Faculty, 2 George St., S Block, Room 701, Brisbane, QLD 4000, Australia.
Md Mazharul
MM
Haque
Queensland University of Technology (QUT), Centre for Accident Research and Road Safety-Queensland (CARRS-Q), 130 Victoria Park Road, Kelvin Grove, QLD 4059, Australia.
Mark
M
King
Malaysian Institute of Road Safety Research (MIROS), Jalan TKS1, Taman Kajang Sentral, 43000 Kajang, Selangor, Malaysia.
Wong Shaw
WS
Voon
D000063:Accidents, Traffic / Q000517:prevention & control; D001334:Automobile Driving; D003906:Developing Countries; D004779:Environment Design; D055593:Geological Phenomena; D006801:Humans; D008296:Malaysia; D015233:Models, Statistical; D011891:Rain; D012424:Rural Population
Developing country; Horizontal curve; Mountainous roads; Random parameters model; Single-vehicle crashes; Vertical gradient