Pedestrian Crossing - Grade Separation
Most pedestrian crashes occur while the pedestrian was attempting to cross the road. One way of preventing crashes between vehicles and pedestrians is placing them at different levels, or ‘grade separating’ them.
In urban situations where pedestrian crossing signals would cause congestion or crashes (due to high traffic speeds), a grade separated pedestrian crossing, such as an overpass (or bridge, footover bridge) or an underpass, may be used. Outside of urban areas in situations where there is pedestrian demand in high-speed environments, this treatment may also be applied.
Grade separated pedestrian crossings reduce pedestrian crashes but they also have some disadvantages:
- they are costly
- they sometimes become crowded with street traders
- pedestrians may avoid them if there are a lot of steps to climb up or down
- if they are not well-lit and patrolled, they may pose a personal security risk
- underpasses are susceptible to flooding and can become unusable if not routinely maintained.
- Reduced pedestrian/vehicular conflict.
- Can help to reduce fatal and serious injuries involving pedestrians and bicyclists.
- Traffic flow improvements.
- Grade-separated pedestrian crossings are more attractive if detour and level difference are reduced by taking advantage of local topography and vertical profile of a road.
- Semi-depressed underpasses can be attractive for pedestrians and non-motorised users.
- Pedestrians tend only to use crossing facilities located at, or very near, to where they want to cross the road. Pedestrian fencing can be used to encourage pedestrians to use crossing facilities.
- Where a lot of bicyclist traffic is present a pedestrian underpass or overpass can be used by cyclists as well as pedestrians, but this will require shallow approach ramps and therefore additional land.
- Consideration should be given to improving accessibility for the mobility impaired. This may include design features such as sufficient width to accommodate wheelchairs and ramps or lifts as an alternative to steps.
The Star Rating Demonstrator is a freely available tool with the iRAP online software, ViDA. With the Star Rating Demonstrator, it is possible to explore the impact that this Safer Roads Treatment has on risk.
Treatment Summary
Costs | High |
Treatment life | 20 years + |
Potential casualty reduction | 60% or more |
Case Studies
