Two people were taken to hospital after a five-vehicle collision on the Coquihalla Highway on Sunday afternoon.
The crash happened at the Great Bear Snow Shed just after 4 p.m., Cpl. Mike Halskov said.
RCMP said snow melting in the northbound lane was leeching over into the southbound lane and then freezing, creating slippery conditions.
The variable speed corridor in that portion of the road had reduced its speed limit to 60 km/h, Halskov said.
A vehicle tried to pass a slow-moving semi-truck but lost control and caused a chain-reaction crash, he added.
Although two people suffered from non-life-threatening injuries, the use of seatbelts likely prevented further injuries, Halskov said.