Investigating the Impact of Road Cross-Section Elements on Crash Occurrence in Urban Areas

Abstract

Appropriate roadway cross-section design is critical due to its impact on safety, capacity, and function of the facility. While it is generally straightforward to assess this impact on capacity and function, it is not always easy for safety evaluation. Literature shows contradictory observations concerning the complex relationship between roadway cross-section elements and crashes, particularly in urban areas. Another important issue is the presence of on-street parking and their safety implications in urban areas. In the current study, safety performance functions were developed to investigate the impact of roadway cross-section elements and on-street parking on crash occurrence using negative binomial distribution framework. A database consisting of six-year crash records, traffic data, and road geometry of urban roads of Antwerp, Belgium was created for modeling. This paper reports how cross-section elements, on-street parking, and exposure contribute to crash occurrence in urban areas and discusses whether the results could be used to improve safety performance of road segments. The results indicated that the effects of number of lanes, segment length, and traffic volume on crash occurrence were significant while that for lane width was not. Parking variable (parking arrangement) was significantly related to "injury", and "injury & fatal" crashes. Roads with higher number of lanes experience more crashes than roads with fewer lanes. Roads with parking were more prone to injury & fatal crashes than no parking settings. To conclude, these findings showed that road cross-section elements and parking settings play an important role in crash occurrence on road segments in urban areas.