Impact of a Contraflow on Travel Times and Speeds

Understanding the impact of a contraflow on traffic, safety, and travel time.

This case study uses Compass Road Intelligence and Custom Data Science.

TfNSW’s Pavement team for Regional and Outer Metro (ROM) was interested in understanding the impact of a contraflow on traffic on the Hume highway, in both directions. Traffic was being redirected onto the other side of the road to allow workers to replace a section of the road.

Specifically, the client was interested in implications for travel time, speed, swerving and braking, and queue length at either end of the contraflow. They had 4 other questions they wanted addressed:

  1. Is the traffic management plan being adhered to?
  2. Are workers on the construction site safe?
  3. How far back does the queue go at either end of the contraflow?
  4. How big is the difference between the actual speed and the speed under contraflow conditions?

The client used Compass Road Intelligence to visually identify the point the contraflow started and ended, causing vehicles to travel onto the other side of the road. This is indicated by the green and red dots switch from one side of the Hume Highway to the other.

A data science dashboard also revealed impacts on average travel time, speed, and queuing:

  • average travel time increased
  • average speed decreased
  • increase in queuing to 31.23%

Data showed that there was a clear impact on average speed and travel time during the times the contraflow was active, as seen by the spikes between 11am and 7pm.