Just before everything spun out of control and the world turned upside down, I was chatting with my guide, a Canadian from Whitehorse. We had just walked across the width of the frozen Takhini River in snowshoes, and now we were loading up the SUV in preparation for the drive along the Alaska Highway to my hotel.

The road looked like a thick sheet of ice. “How can we possibly drive on that?” I asked.

“You treat the Alaska Highway the same way you treat brown bears in the wild. You must show respect at all times. If you drop your guard, even for a second, you’ll get savaged.” Five minutes later, we got savaged.

The vehicle was struggling uphill. My guide applied more gas to get us up the final stretch. At the brow, he turned to me and said, “Made it!” At that instant, as the road dropped away steeply, the back of the SUV stepped out.

Gathering speed, we pirouetted down the highway, narrowly missing an oncoming truck before cartwheeling into a snowdrift. When we came to rest, I was dangling upside down, secured by the seatbelt around my waist. I unclipped it and dropped onto the ceiling of the vehicle amid a clutter of snowshoes, camera equipment and the remnants of our bag lunches.

By the time I pushed the door open and wormed my way out, the guide was already standing in thigh-deep snow assessing the damage. “Could have been worse,” he said matter of factly. “ ’Least the vehicle seems okay.” And then, as an afterthought, “Are you okay?”

The accident represents one of the lowest points in my love-hate relationship with the Alaska Highway. It’s a road I’ve tackled several times, in all seasons. On clear, fall days, there’s no place I’d rather be driving. The road wends its way northwest, alongside the snow-capped Wrangell-St. Elias Mountains in the Yukon and then through the foothills of the Alaska Range, with the autumnal roadside vegetation glowing gold and red.

The bible for all drivers on the Alaska Highway is The Milepost, a hefty directory that details the sights and services for the full length of the epic route, from Mile 0 at Dawson Creek in British Columbia to Mile 1520 in Fairbanks, Alaska.

Construction of the highway was an astonishing achievement, initially carried out by the United States Army Corps of Engineers in 1942 to establish a World War II land supply route between Alaska and the Lower 48. African-American soldiers carried out much of the toughest work; the Black Veterans Memorial Bridge, spanning the Gerstle River at Mile 1392, commemorates their contribution.

The highway served as a vital wartime lifeline, but since then it has become as much a leisure attraction as a transport route. In the warm months, the route sees a constant flow of SUVs and RVs. Few tourists attempt the drive in winter. Standing beside our turned-over vehicle on the roadside near Whitehorse, I could understand why.

The truck we almost collided with continued without stopping. We flagged down the next truck, and with ropes and chains the driver righted our vehicle and dragged it back onto the road. After a cursory inspection, my guide deemed we were fit to go. The crash, which could so easily have claimed our lives, cost us just 15 minutes.

We resumed with heightened respect for the road and the men who made it, cautiously rattling our way back to town. In a curious way, I was grateful to have been reminded of the Alaska Highway’s barely tamed disposition. It’s more than a road. It’s the drive of a lifetime.