The M8 motorway has been closed in both directions near Harthill, at junction 4a westbound and junction 5 eastbound, following a serious collision this morning.
Emergency services were called to the incident about 04:05 on Friday morning, and remain at the scene.
Officers have also been called to Junction 6a at Chapelhall where the road is blocked eastbound due to a separate collision.
Drivers travelling east face delays of over one and a half hours approaching junction 6a.
Traffic Scotland said those driving westbound from junction 4 Whitburn faced delays of 20 minutes.
It added that the road was likely to remain closed for some time.
Commuters are being urged to find alternative routes.