A trial with rumble strips was conducted at 14 railway level crossings protected by passive signs, of which 11 crossings had Give Way signs and 3 crossings had Stop signs. The crossings were located on high speed rural roads within Wheatbelt regions of Western Australia. The rumble strips were installed at each approach to the crossing. One group of strips was installed at the crossings protected by Give Way signs and four groups of rumble strips were installed at the crossings protected by Stop signs. Changes in vehicle speeds were used as surrogate measures of changes in driver alertness after installation of the rumble strips at the two types of crossing protections.
Two speed surveys were conducted at each of the crossings, before and after the installation of the rumble strips. Comparison of the mean speeds before and after installation of the rumble strips indicated that the strips had a significant effect on driver speed behaviours at the crossings with Stop signs, while the effect was negligible at the crossings with Give Way signs. The installation of rumble strips at the crossings with Stop signs resulted in the mean speed reduction of approximately 5 km/h over the entire section of road of approximately 500 m including the crossing. The effect was strongly associated with the number of groups of rumble strips installed on the pavement at the approach to the crossing.
The study found that a single group of rumble strips installed at the crossing protected by Give Way signs was insufficient to alert the drivers of possible hazards ahead as measured in terms of reduction in speeds at the approach to the railway level crossing. An increased number of rumble strips groups is recommended for the Give Way protected crossings similar to the Stop sign protected crossings. The increase in the number of rumble strips groups is not expected to significantly reduce the vehicle travel speeds, beyond what was observed at the crossings protected by Stop signs, that would increase likelihood of conflicts between vehicles and the train. The increase in driver alertness is expected to minimize possible hazards of conflicts between vehicles and trains at the crossings characterized by extremely low traffic and train volumes.