A review was undertaken of traffic conditions and noise associated with the Gungahlin Drive Extension (GDE). This was in the context of reviewing the speed limits that should apply to the GDE.
Noise measurements were undertaken in 2011-12 at several locations in Aranda and along the GDE corridor. These results were compared to those from monitoring undertaken at the same locations prior to construction and again after the opening of stage one of the GDE.
These found very little change in noise at each location, with many locations having slightly reduced noise due to the noise mitigation measures, such as mounds and barriers, which were included in the project.
All noise levels were found to be below the ACT traffic noise guidelines. Modelling was also undertaken which showed that, for any property where GDE was the dominant source of traffic noise, it would increase by less than 2 dB if the speed limit was increased to 90 km/h and the traffic volume increased. This again would be within noise guidelines.
GDE noise report(PDF 675KB)
An independent report, which looked at engineering and road safety aspects associated with the current GDE road design, recommended that the speed limit be increased from the previous 80 km/h to 90 km/h.
As a result of these assessments, Roads ACT reviewed an earlier decision to maintain the speed limit at 80km/h and decided to increase the GDE speed limit to 90 km/h for the section between the Barton Highway interchange through to the Glenloch interchange.
To ensure consistency the 90km/h speed limit also includes the connection ramps from Tuggeranong Parkway to William Hovell Drive, the City bound connection ramps and the William Hovell City bound ramp. The 90km/h speed limit came into effect in March 2012.
GDE speed limit report (PDF 675KB)