Victoria Police have confirmed the details of the two people who sadly lost their lives in a three-vehicle collision on the Western Highway on Tuesday.

A semi-trailer crashed into the rear of a car turning into a rest stop on the Western Highway about 12.20pm near Golton Road.

The car was pushed into oncoming traffic, colliding head-on with another vehicle.

The female passenger of the first vehicle, and the female driver of the second vehicle died at the scene.

The male driver of first vehicle sustained life-threatening injuries and will be airlifted to hospital.

The uninjured male truck driver was arrested and is assisting police with their enquiries.

The Western Highway was closed for most of Tuesday while investigations took place.

At lunchtime on Wednesday there was still a reduced speed limit of 80km/h through the site.

Updated Wednesday, 1pm