A smooth commute
I feel that creating an expressway over the current expressway would alleviate traffic. There could be a traffic signal to cue cars.
By adding a second expressway over the current expressway it would not complicate the design. Entrance and exit to the highway can be controlled by a traffic signal that could signal drivers which one of the highways to take, the lower or upper highway. This could serve to ensure that traffic is evenly dispersed. This would avoid congestion.