​The problem

The congestion hotspot southbound on Mitchell Freeway at the busy Charles Street on-ramp is a well-known issue on Perth's roads. Four lanes of traffic are reduced to three lanes and freeway traffic is forced to merge with high volumes of entering traffic from the Charles Street on-ramp.

Further south a fourth lane joins the freeway again from Market Street.  However, this on-ramp has relatively low volumes of traffic by comparison.

The solution

As part of the works we are undertaking to improve merge points along the freeway, we identified an opportunity to provide an additional lane by changing the line markings on Mitchell Freeway southbound, between Charles Street and Market Street.

The works included removing the merge point where Mitchell Freeway meets Charles Street, and reducing the bottleneck currently experienced in this area. The project has improved traffic flow by increasing capacity for freeway traffic and adding new merge lines to the under-utilised Market Street on-ramp.

Travel speeds have improved by 15km/h (65 per cent) between Vincent and Market streets in the afternoon peak for commuters heading south.


Before construction: Mitchell Freeway southbound - Charles Street to Market Street


After construction: Mitchell Freeway southbound - Charles Street to Market Street



Completed April 2016.

Last Updated: 11 January 2017