View from inside a car looking at other vehicles on a motorway with a digital effect overlaid ; View from inside a car looking at other vehicles on a motorway with a digital effect overlaid ;

Austroads Connected and Autonomous Vehicles Traffic Sign Recognition Trials, Australia and New Zealand

How do you teach a car to read traffic signs?

How do you prepare for a future when cars can read? Arup recently undertook a study on behalf of Austroads – Australasia’s peak body for road transport and traffic agencies – to help road authorities do just that.

The study, Implications of  Traffic Sign Recognition (TSR) Systems for Road Operators, looks at the issues faced by road operators in ensuring signage takes into account the way in-vehicle TSR systems ‘read’, understand and react. It combines real-world automated vehicle trials and research into world best-practice for TSR technology. As part of the study, development and commercially available vehicles were tested at the Australian Automotive Research Centre test track in Anglesea, Victoria, as well as in Melbourne, Sydney and Auckland.

Arup worked in partnership with Safe Systems Solutions and Monash University Institute of Transport Studies to identify current issues, provide recommendations and develop an information and engagement program for considering how traffic sign design should respond to current and future TSR technologies.

Austroads’ studies and guides inform the design, construction, maintenance and operation of the road network in Australia and New Zealand. All road agencies in the region have adopted the guides, so Arup is pleased to be involved in a study that will play an important role in helping shape the future of road design and driverless vehicles. ”

Yasmin Roper head shot Yasmin Roper Civil Engineer

In developing the study, Arup consulted extensively. We worked with Australian and New Zealand road agencies, members of Austroads’ Traffic Management Working Group and relevant Australian Standards committees for traffic signs, as well as signage and vehicle manufacturers and camera technology specialists.

Key findings from the study include:

  • Difficulty reading electronic speed signs

  • Limited ability to read advisory and information signs. Cars were unable to understand anything text based such as “End Zone” and “Speed Ahead” signs 

  • Inability to read text qualifications such as time dependent or vehicle specific speed zones. When driving through time dependent school zones the car would only read the speed limit and adjust speed accordingly, regardless of time of day

  • Intricacies in sign placement. Signs for adjacent roadways located close together resulted in cars registering the incorrect speed limit, eg mistakenly reading nearby exit ramp speeds despite remaining on the main motorway

  • Importance of sign maintenance to ensure consistent readability

  • Inaccurate GPS spatial databases and associated speed zone information.


While there is a need for vehicle manufacturers to continue to develop TSR technology, the report urges road operators to take action to encourage these improvements. Now available on the Austroads website, the final study includes the following recommendations:

  • Development of TSR criteria for electronic signage to increase readability

  • Stronger harmonisation of sign design across the region and a focus on reducing text heavy signage

  • Incorporation of machine vision audits of new sign installations

  • Consideration of TSR camera system field of vision when deciding on sign placement at locations such as freeway exit ramps and shared gantries

  • Implementation of education programs for traffic managers, local governments and state road agency employees. 


This key study will provide Austroads and relevant road agencies with a deeper understanding of the implications of TSR technology. It will set a path forward for road operators, transport authorities and key stakeholders – helping to prepare our road networks for the introduction of more efficient mobility options. ”

Mark Rowland Mark Rowland Associate, Cities & Transport Planning