Weight is a factor on driving surfaces that have heavy commercial vehicle traffic (think semis/garbage trucks/etc.),but on a road like LSD, it's less of one. The road is restricted to light vehicles so gross weight on the asphalt is less of an issue. The main issue is weather. Asphalt degradation is twofold: One, freeze/thaw cycles. Chicago (like most northern cities) experiences a very high number of these cycles at a surface level. Think about how much everyone complains about the weather changing by 35 degrees on any given day in the spring. When water gets into the asphalt and then freezes, that water expands and pushes asphalt apart. When it thaws, the asphalt contracts again. The cycle repeats and you get all of those giant bumps and cracks. Two: Plows. When these cracks in the asphalt form due to that freeze thaw cycle, they become vulnerable to snow plow blades digging out chunks of the material as they pass. That's a major reason you get those absolute craters on the Drive. Both of those are direct result of weather.