Police say they have received reports that the Fiat Stilo was travelling west on the eastbound carriageway of the M8 when it collided with a lorry, which was travelling east.
The crash happened at around 1am today around one mile east of Harthill.
The east-bound carriageway of the M8 was blocked after the vehicles burst into flames.
The 19-year-old driver of the car, who was from Bathgate, died at the scene.
The 39-year-old HGV driver was not injured but was treated in St John’s hospital for shock.
A spokesman for Lothian and Borders Police said: “There are reports the Fiat Stilo was travelling west on the eastbound carriageway, having joined it at junction 3A, before it collided with the HGV which was heading east.
“The eastbound carriageway of the M8 was closed between junction five, Shotts, and junction four, Whitburn, for around five hours while investigations were carried out at the scene. One lane reopened around 6am, with the full carriageway reopened about 8.50am.
“We are investigating the circumstances that resulted in this collision and would encourage any motorists who were on the road at the time to contact police immediately,
“Similarly, anyone with any other information that can assist police with their enquiries are also asked to come forward.”