Estimation of Crash Severity on Mountainous Freeways in Chongqing

Abstract

Mountainous freeways always suffer from accidents due to special terrain, weather conditions, driving environment, and so on. Based on the records of 898 accidents that occurred on mountainous freeways in Chongqing during the past 6 years, the partial proportional odds model is used to identify the factors affecting the accident severity. The time of the accident, season, involvement of trucks, accident characteristics, speeding, maximum driving experience of involved drivers, and weather and road conditions are found to be important for the levels of accident severity. Zero to 6 a.m. and 19 to 24 p.m. are the times prone to serious traffic accidents. The probability of serious traffic accidents in summer and autumn is greater than that in spring and winter. Once a truck is involved in an accident, the consequence is often more severe. Turnover and speeding will result in a grave accident. When there is an experienced driver, the probability of serious traffic accidents is low. The fog is extremely unfavorable weather conditions. The probability of serious accident happening in the downgrade, ramp, curve, bridge, and tunnel sections is greater than the others. The results aim to provide valuable reference for traffic safety on mountainous freeways.

Influence of Environmental Factors on Injury Severity Using Ordered Logit Regression Model in Limpopo Province, South Africa

“…According to a study conducted by Meng (2017) estimating crash severity on mountainous freeways in Chongqing, accidents occurring between 19 and 24 p.m. were found to be more severe because of the driver's visual response, psychological load, and the road environment. The study also found that the degree of mutual adaptation is more unfavourable to the driver [ 32 ]. It was also stated that the likelihood of major traffic accidents is higher in summer and autumn than in the spring and winter.…”

What leads to severe multi-vehicle crashes on mountainous expressways in Western China?

“…A large proportion of these records were identified as occurring along roads in mountainous areas (National Bureau of Statistics of China 2019). Alarming statistics in China show that mountainous expressways are susceptible to a high frequency of multi-vehicle crashes, as well as more severe consequences (Zhang et al 2016; Meng 2017).…”

“…Unlike single-vehicle crashes resulting from loss of vehicle control associated with driver error or negligence like excessive speed, alcohol usage and driving fatigue (Rusli et al 2017), it is extremely difficult to determine the causes of multivehicle crashes, especially when occurring on mountainous expressways, due to the adverse traffic environment of the terrain, which includes tight curves, steep slopes, the existence of bridges and tunnels, and changing climatic conditions (Meng 2017;Wang & Prato 2019;Wang et al 2019a). The huge economic loss and serious social repercussions that are incurred by crashes involving multiple vehicles have attracted increasing attention worldwide from researchers and traffic managers (Wang & Prato 2019; Wang et al 2019a; Dong et al 2018;Rezapour et al 2019), especially for those occurring on mountainous expressways.…”

Determination of Curve Speed Zones for Mountainous Freeways

“…ese include factors such as downhill section, curved slope combination section, overspeed, and an absence of safe following distance [3]. Meng et al found that speeding, driving experience, weather, and road conditions all have an important impact on the severity of mountain freeway accidents [4]. Wang et al studied combinations of different road alignments and horizontal and vertical plane directions.…”