Perth motorists can expect major gridlock as a string of rail and road projects are rolled out this year.

The state government has called the works, worth $8 billion, ‘short term pain for long term gain’.

The biggest disruption will be the $290 million Tonkin Highway Gap project and $237 million for a new bridge over the Kwinana Freeway.

Other projects include $64 million on the Wanneroo Interchange and $47 million for smart technology to open and close lanes and adjust speed limits along the Kwinana Freeway.

Six million will also be spent on informing motorist on delays.

Major construction will also kick off along various rail lines in the coming years.