Safety Alert – Advance Warning Vehicles Struck

Main Roads WA has recently released a temporary traffic management alert in relation to advance warning vehicle incidents. This alert has come from recent incidents in the industry where the advance warning vehicle has been struck causing serious damage and injuries. 


In the past few months there have been 2 incidents involving an errant vehicle colliding with an Advance Warning Vehicle (VMS Ute) on the Freeway. Main Roads is continuing to investigate these incidents; however, reports are that the vehicle occupants suffered relatively minor injuries. Both incidents had the potential to have a far more serious outcome. 


The Austroads Guide to Temporary Traffic Management and Australian Standard 1742.3 require warning signs, such as a Worker (symbolic) sign, to be placed in advance of workers and/or machinery to warn motorist of their presence on or adjacent to the travel path.  

Advance warning may be provided by static sign or by vehicle or trailer mounted VMS.  

There are risks associated with implementing these signs that need to be considered and mitigated. In particular the following should be considered when working on the Freeway:  

  • Traffic Management Workers on foot must be protected by a Truck Mounted Attenuator (TMA) when implementing traffic management  
  • Traffic Management Vehicles must not stop in the live running lane unless protected by a TMA 
  • Occupants of vehicles used as advance warning vehicles are unprotected and at risk of severe injury if hit by an errant vehicle. This needs to be risk assessed to determine if this is an appropriate method of advance warning. If the risk is determined to be unacceptable either the occupant should be safely removed from the vehicle or alternative advance warning should be provided e.g additional TMA or static signs 

Future Actions and Considerations 

Following these recent incidents Main Roads WA will investigate making amendments to the requirements for advance warning within the Code of Practice. In the meantime, the following can be considered as a variation to standard that is assessed and endorsed by a person with RTM accreditation: 

Advance warning signs (including vehicle or trailer mounted VMS) may be omitted on Freeways and high-speed grade separated highways where all of the following applies: 

  • The removal of the advance warning is supported by a risk assessment undertaken by an RTM and a variation to standard is completed and then accepted by Main Roads 
  • The works are Short-term low impact works as per AGTTM Part 5 or the works do not require a speed reduction 
  • A TMA is deployed to protect the work area (TMA to display required TTM signs) OR the work area is behind a road safety barrier 
  • The work area, including TMA, is not located within a running lane (e.g. works on verge, shoulder or emergency lane) 
  • Approaching vehicles have at least 200 m of sight distance to the worksite 

Further information  

For further information or to provide feedback on this proposal contact Main Roads WA  

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