This is increasingly being done with congestion charges and time-dependent road or bridge tolls, but it still remains difficult, from a practical perspective, to maintain a continuous auction of road capacity.
Notably, wireless deployments differ from road use in that using a wireless spectrum assignment requires significant deployment time and capital investment, meaning when a frequency range is assigned it's reasonable to expect and allow a single entity to control that range for an extended period. With roads, on the other hand, a single use can be as short as a few minutes, meaning a similar auction would need to re-occur hundreds or thousands of times a day.
Further, if wireless spectrum ranges are not pre-assigned, it becomes quite difficult for multiple entities trying to use the same range to coordinate to avoid interference that would render the range useless to both. Roads, on the other hand, can be reasonably shared by multiple users without any coordination ahead of time.
Because of these practical difficulties, and the lack of an inherent need for usage assignments, most roads are not tolled or auctioned, and the result is heavy congestion in highly-sought-after routes at peak times.