Commuters making the rat run through Sydney's inner-west will face increasing congestion as a result of the WestConnex motorway, as new modelling reveals peak hour traffic will triple in volume on some local streets over the next five years.

The traffic study, commissioned by the Inner West council, predicts hundreds of additional cars will crawl through local streets and arterial roads in order to access the WestConnex motorway or avoid it, once construction is completed.

Parts of Haberfield are tipped to be hit with a substantial increase in traffic once WestConnex is completed. Credit:Nearmap.com

According to the study, the worst-affected suburbs will be Haberfield and Ashfield, where traffic on at least four local roads will increase by more than 200 per cent by 2021.

Inner West mayor Darcy Byrne said the study showed that "the opening of stage one of WestConnex will result in the mother of all rat runs through suburbs like Ashfield and Haberfield".



"Thousands of Inner West residents will be forced to endure bumper-to-bumper traffic in their daily commute to work and when dropping their kids off to school," he said.