Evaluation of Effectiveness of Stop Sign Treatments at Highway–Railroad Grade Crossings

The safety benefit of stop sign treatments at passive highway–rail crossings has been a subject of research for many years. The objective of this study is to assess the effectiveness of the stop sign treatment on crossing safety. Using the FRA database, the research focused on 26 years of vehicle–train accident history in the United States from 1980 through 2005. A before-and-after and cross-sectional statistical analysis was conducted for 7,394 public highway–railroad grade crossings that were upgraded from being controlled only by crossbucks to stop signs, without other traffic control devices or automatic countermeasures. The study found that accident rates based on annual accident frequency per 1,000 crossings were significantly higher during the period when crossings were controlled only by crossbucks than when they were controlled by stop signs. Further, this study developed negative binomial accident prediction models for paved and unpaved highway–rail grade crossings that included the effect of stop sign treatment. Taking account of specific attributes of crossings controlled only by crossbucks, decision makers and traffic engineers can use the models to examine the accident risks at crossings and assess the potential effectiveness of stop sign treatment.