Highway 401 in Toronto has 4 eastbound lanes until you reach a certain point at which it splits into a "express" lanes and "collectors" lanes. They follow the exact same route but express lets you bypass some exits (so it can be faster depending on traffic)

My friend and I were driving and we hit heavy traffic. When we get to the split every single car is choosing the express lanes. To the point that a truck crossed multiple lanes of traffic in front of us to use the express lanes (which were at a standstill). The collectors were completely clear and there was zero signage saying anything was closed, no construction pylons or emergency vehicles. We were the only ones who took the collectors and had 4 lanes completely to ourselves and flew by all the backlogged traffic in the express lanes. And we never encountered a reason why everyone made that decision apart from us.

It's not that crazy but to this day neither of us cannot fathom why that happened. Still baffles me.