The State Government will spend almost $35 million on four bicycle infrastructure projects to be announced in its Budget next week.

It will also reveal another $37 million in renewed cycling grants for local governments and a focus on new cycle paths on railway and freeway reserves within 15km of central Perth.

The four big projects to be funded over four years are paths along the Mitchell Freeway extension from Burns Beach Road to Hester Avenue, Great Eastern Highway between Bilgoman Road and Mundaring, the Reid Highway dual carriageway and Gateway WA.

Transport Minister Dean Nalder said the commitment would improve safety and bike network connections.

He said the Government was determined to create an integrated system that gave transport options to get to and from work, leisure and other destinations.

"Cycling infrastructure needs to be considered an important part of all major transport projects, so with every major new road constructed by this Government, you will likely find a new bike path," Mr Nalder said.

He promised innovative options to separate cyclists and vehicles to improve safety and encourage bike use.

The funding comes as the WA Auditor-General investigates the adequacy of Perth's bike network for a report this year.

Mr Nalder said the Government had spent $101.6 million over six years on cycling networks, resulting in 221km of off-road shared paths and 71km of on-road bike lanes.

The $37.71 million in the Budget for local government grants over four years would be for cycling infrastructure and to develop bike plans.

In the most recent grants, 33 local governments shared more than $2.7 million to create, design or upgrade 22.1km of paths and 1.4km of on-road bicycle lanes.

They include a 1.9km shared path on Safety Bay Road in Baldivis, a 1.4km bike lane on Scarborough Beach Road, a 1.3km Busselton bypass cycleway between Strelly Street and Clydebank Avenue and a 2.8km shared path on Coalfields Highway in the Shire of Collie.

Treasurer Mike Nahan said the funding was a record for bike infrastructure, with a significant amount on paths close to the city.

"For instance, the path along the Fremantle line between Shenton Park and Loch Street stations is under construction," he said.