Coquihalla Highway is an extreme freeway located in southern British Columbia, Canada. It’s part of the Highway 5 and is around 200km long. It’s one of the worst roads in all of North America in winters. There were 32 fatal crashes between 2004 and 2013 (according to ICBC). In spring, summer or fall, it's a breeze, but in winter there are at least 400-500 accidents and plenty of fatalities.
This asphalted road is the main highway link between Kelowna in the Okanagan Valley and Vancouver B.C. Make sure you get your vehicle and yourself well-prepared before driving this road. It is very steep at both ends and although it is a modern highway, most truckers avoid traveling on it due to the extra gasoline expense that the steep inclines create. The road climbs up the Coquihalla pass, a mountain pass at an elevation of 1,244 m (4,081 ft) above the sea level.
Trucks have been known to avoid the route due to the long, steep climb up to the summit and the long, steep descent, but most motorists don't have any hesitation about driving the route in spring-summer-fall conditions. Winter driving is indeed dangerous, but that is more a reflection of the high elevation and mountainous terrain rather than the road itself. To quote Highway from Hell's Jamie Davis, “I can’t criticize the Coquihalla. The main factor is you’re driving over a mountain. It’s not a flat road, it’s a mountainous highway... It requires skill to drive.” At high elevations it can sometimes get to be -30 deg. C in cold winter weather. The highway is pretty good, some sections have frost heaves and uneven pavement but it's 2 lanes each way so slower traffic like trucks are not an issue.
Check weather forecasts before leaving home, and remember that it becomes cooler and often more prone to storms at higher elevations. Winter surprises are a real fear, sudden snow storms, blowing snow and fog, often make winter driving hazardous and slow. Smart drivers have lots of gas, carry winter clothing, a candle (for warmth) and sleeping bag in the car ' just in case' (chances are that you will never need those extras).
The Coquihalla Highway - Phase 1, Hope to Merritt - was completed in time for Expo 86 in 1986. Careful preparation for your trip will ensure that if, and when, things do go wrong, you are prepared for the situation. Make sure your vehicle is in good shape with summer coolant and good brakes and tires.