#21 Temporary Traffic Management Technology

Smart traffic management technology applies to roadworks and other temporary traffic management (TTM) scenarios, as well as to the broader network where relevant devices are often installed permanently (see Post #20). As is the case with intelligent transport infrastructure generally (e.g., smart motorways), linked cameras, sensors and variable message signs (VMS) are key technological features of an advanced TTM approach. These systems provide valuable information to road users and assist authorities with speed management and incident response. Additionally, devices to minimise workers’ exposure to traffic are increasingly used and subject to ongoing development and innovation. Overall, these measures can improve safety for workers and road users alike, as detailed in the Austroads Research Report AP-R544-17.

Information provision

Conditions at roadworks can be unpredictable and hazards are not always visible to road users. VMS are used to provide important information on changed conditions and relevant hazards. When networked with sensors and other devices, real-time updates can alert drivers to downstream signal status and expected delay times. Such combinations are evident in sophisticated queue warning systems, which currently have limited application in Australia.

Sequential lighting can enhance path delineation to provide clearer guidance to motorists. Intrusion alarms use sensors to detect and alert workers to errant vehicles entering a work area or otherwise violating work zone controls, including speed limits.

Speed management

Variable speed limits (VSL), delivered through linked VMS, allow roadwork speed limits to be adjusted remotely according to conditions (e.g. when sites are active/inactive). Speed feedback signs have proven effective for encouraging roadwork speed limit compliance. Automated enforcement of roadwork speed limits is relatively new but currently being trialled in Queensland and likely to be adopted in other jurisdictions.

Exposure reduction

Human traffic controllers can be removed from the traffic stream using portable traffic lights (PTL) and/or boom gates. Both can now be integrated with upstream VMS for greater effectiveness and flexibility in appropriate conditions.

Installation and removal of devices is one of the most hazardous activities for roadworkers. Remote control of VMS units for adjusting messages and/or speed limits reduces the exposure of traffic controllers to traffic. Automated traffic cone deployment trucks can also negate the need for workers on foot during site set-up/removal.