Perth's road network faces more upheaval with new dedicated bus lanes planned for some of the city's most congested areas.
The plans, revealed in tender documents lodged by the Public Transport Authority, are designed to ensure buses do not run late in the face of Perth's increasing traffic congestion.
They include removing buses from Barrack Street and using the Mounts Bay Road median strip for buses.
PTA spokesman David Hynes said it was no secret Transperth buses were affected by congestion "just like every other vehicle on the road".
"We accept that these delays cause frustration to our passengers," Mr Hynes said.
"As a result, the PTA is embarking on a number of projects aimed squarely at improving bus on-time running and reliability."
One project is the transfer of northbound buses from Barrack Street to William Street.
This will include creating a left-turn lane at the intersection of William and Hay streets, a new bus stop on the western side of William Street between Murray and Hay streets and creating a bus-only right-turn lane at Wellington Street.
The work is expected to begin this year. Mr Hynes said modelling suggested the changes would improve traffic flow through the CBD.
"Each day, hundreds of buses run in a north-south orientation along Barrack Street," he said.
"Due to the Elizabeth Quay development, the PTA has been investigating ways to move buses through the centre of the city.
"We believe these changes will improve the reliability of services and shorten journey times, while not contributing to congestion."
Another project will be the creation of a 750m dedicated bus lane on Stirling Highway, in front of the University of WA.
The plans include converting a lane on Albany Highway into a bus-only right-turn queue-jump lane at the intersection of Nicholson Road and creating a bus-friendly roundabout near QEII hospital, at the corner of Hospital Avenue and Aberdare Road.