Traffic signals are set to be installed at motorway on-ramps across Sydney over the coming years to stagger the flow of vehicles onto major thoroughfares and to reduce bottlenecks.

As part of a $600 million project, a trial of the first quick-change traffic lights will begin next week at the Reservoir Road on-ramp to the M4 motorway at Blacktown.

The on-ramp lights are designed to improve traffic flow along the M4 motorway. Credit:Nick Moir

And, by next year, traffic lights on on-ramps to the M4 between Mays Hill and Penrith, and signals on overhead gantries over the motorway, are expected to be switched on.

The technology is similar to that used on motorways in Melbourne and Auckland.