Prime Minister Scott Morrison will splurge another $1.6 billion on infrastructure projects across WA, as the Coalition works to shore up voter support ahead of the May election.

Mr Morrison, who arrived for a fundraiser in Perth last night, will today announce the major Budget boost for road and rail projects aimed at addressing voters’ concerns about congestion.

Targeting the five marginal seats the Coalition must keep to remain in government, Mr Morrison will announce a raft of projects aimed at easing congestion around Perth, along with funding for the State’s main highways and major regional roads.

Most of the projects are receiving Federal funding for the first time, while for others the Government is topping up its commitment.

“We are prioritising investment in the major projects needed to better support regional areas, ease congestion in and around Perth and reduce the terrible impact of road trauma by delivering safer roads,” Mr Morrison told The West Australian.

The $1.6 billion comes on top of almost $5 billion in road and rail projects announced by the Coalition over the past two years and after Opposition Leader Bill Shorten was in Perth last week to announce an extra $200 million for rail projects.

The key traffic projects include $207 million to remove level crossings at Oats Street in Carlisle, Welshpool Road in Welshpool and Mint Street in East Victoria Park, along with $115 million for the dilapidated Fremantle Traffic Bridge.

Mr Morrison, pictured, said the level crossings were “some of the worst across Perth” and removing them would deliver significant amenity, productivity and congestion-busting benefits.

The revamp of the 257m Fremantle Traffic Bridge over the Swan River will include a road bridge and a track rail bridge after the 80-year-old bridge was added to Infrastructure Australia’s list of priority projects.

“The upcoming Budget will continue the Liberal-Nationals Government’s firm commitment to ensuring Western Australia gets its fair share of infrastructure funding now and into the future,” Mr Morrison said.

Extending Tonkin Highway will also get a boost with the Federal Government chipping in an extra $151 million, meaning it will fund 80 per cent of the project’s cost so work can get under way more quickly.

Regional projects have also secured Budget funding, with $140 million for the Albany Ring Road, $122 million more for the completion of the Bunbury Outer Ring Road, and money for other regional road projects. Nationals leader and Deputy Prime Minister Michael McCormack said the regional projects would be a boon for regional WA.

Finance Minister Mathias Cormann, who consulted with the WA Government on which projects were most needed, said the funding boost was “not just numbers”.

“These are commitments to a better quality of life for our commuters who will be able to spend more time with their families, while also delivering a stronger economy through more efficient freight and transport links,” Senator Cormann said.

He said the Federal and WA governments would continue to work on details of the Perth City Deal, which will focus on Metronet and managing the city’s growth.