The incident occurred at around 1.15pm on Saturday on the M8 between Whitburn and Bathgate.
All lanes are currently closed on the eastbound carriageway at Junction 4.
Police and emergency services are on the scene.
It is understood that one woman is being treated for injuries at the scene.
Motorists planning to travel eastbound on the M8 are advised to use an alternative route and allow extra time for their journey.
Sign up to our newsletter: enter your email in the box at the top of this article to get daily updates straight to your inbox.