Two dead in separate Vic road crashes

One motorist is dead and another injured after a two-car crash in which one vehicle burst into flames in western Victoria.

It's the second fatality on the state's roads within a few hours.

The unidentified driver died at the scene when their car burst into flames while the other male driver was taken to hospital with non-life threatening injuries after the collision in Lubeck at 2.40pm on Thursday.

Both drivers were the only occupants of their cars.

Police have closed off the accident site at Horsham Lubeck and Murtoa Glenorchy roads as investigators examine the scene.

Earlier on Thursday, a woman died and a man was airlifted to hospital after a car and truck collided in Victoria's northwest.

Police believe a car veered onto the wrong side of Wimmera Highway in Marnoo East about 1.30pm and smashed into a truck, killing the female driver, severely injuring her male passenger and trapping the truck driver in his rig.