Understanding sudden braking and swerving on a narrow bridge.
This case study uses Compass custom services and Road Intelligence
The Heathcote Road Bridge over Woronora River (HRB) was identified as a higher risk location because of a narrow lane width on the bridge. A study was done to investigate how motorists interact with the segment of road, if there are any identified behaviours, and if any updates to the bridge should be done.
The HRB has a high traffic volume and a speed limit of 70 km/h. The bridge section of the road is approximately 6.7m wide but is used by vehicles of varying size (including trucks). With a narrow width, it is hypothesised that there could be potential conflicts occurring at the approaches of the bridge.
Using Compass custom data services in the study, it can be observed that those entering the bridge are slowing down. Vehicles rush to slow down due to the narrowness of the bridge. As drivers exit the bridge, speed returns to normal. This movement can be observed in the following map.
Through Road Intelligence, evidence of sudden deceleration can also be seen in the graphs.
Heading north there are cases of harsh braking and accelerating. There are g-forces exceeding 0.4 indicating violence.
Instances southbound are also similar. There are cases above and beyond 0.4 especially when it comes to braking.
Results show drivers slowing down as they enter the bridge from both directions, creating a chokepoint on the road. This happens because the width of the bridge is too narrow for fast driving behaviour so updates are needed. A current project proposes that the bridge be widened.