Question - Roads

1. Why were the speed limits changed from 80km/h to 60 km/h on (a) Baldwin Drive (Chuculba Crescent to Gundaroo Drive), (b) Gundaroo Drive (Baldwin Drive to Ginninderra Highway) and (c) Gundaroo Drive (Chuculba Crescent to Barton Highway).
2. What traffic analyses are completed to facilitate a speed limit change. 

(1) (a) Through a risk assessment project, Roads ACT identified the 80km/h northern section of Baldwin Drive (between Maribyrnong Ave north and Gundaroo Drive) to have a higher risk of fatal and serious injury crashes compared to other sections of Baldwin Drive with a speed limit of 60km/h.

As such, in late 2023, the northern section of Baldwin Drive was reduced to a single lane in each direction and the speed limit reduced to 60km/h. New line marking was introduced which narrowed the carriageway and created a sealed shoulder. This type of treatment improved the risk rating of this section of road and will reduce the risk of fatal and serious injury crashes. It also makes the speed environment consistent with the remainder of Baldwin Drive.

As well as safety benefits, the works on Baldwin Drive are also intended to discourage motorists ‘short cutting’ via Baldwin Drive to get to / from Ginninderra Drive, therefore encouraging the use of the newly duplicated Gundaroo Drive as the main arterial road in the area. 

(b) In 2012, TCCS engaged a consultant to undertake the detailed design of the Gundaroo Drive (formally William Slim Drive) duplication. As the project evolved the ‘Safe System approach’ became incorporated into National Road design guides and was included in the design process. 

A key principle of the Safe System approach is a shift of responsibility from an emphasis on road users being responsible for their behaviour on the road, to a greater responsibility for road system designers and managers to build safeguards into the system to prevent injury causing crashes.

As part of the Safe System Assessment in the design process, it was noted that one effective way to reduce crash risk and crash severity outcomes along Gundaroo Drive would be to lower the speed limits to 60km/h. As such the reduced speed limit for the newly completed sections of Gundaroo Drive was introduced as a short-term trial. Recently, this speed limit has been increased to 80km/h following a review of traffic / safety conditions on that section of road.

(c) As above.

(2) TCCS has adopted the Australian National Risk Assessment Model (ANRAM) and the Austroads ‘Safe System Approach’ based on the road hierarchy, current and predicted traffic flows, and aimed at improving the safety and reducing the risk of fatal and serious injury clashes on these roads. These measures are reviewed periodically, and changes made where required.