I have no hard data to back this up but I suspect that people are driving slower, using cruise control more and generally not stomping on the gas pedal due to the significant increase in gas prices lately. All well and good for safety but there will be some unintended consequences to higher gas prices and slower drivers.
Municipalities will start losing revenue they have counted on from speedy drivers. I predicts cities will start raising taxes in order to compensate for this (God forbid they should cut their budgets!) They will also start raising the fines to start compensating for the loss.
Insurance companies will make bigger profits because accidents will be reduced due to people driving at safer speeds. The insurance companies will of course be criticized for making more profit during an economically difficult time.
Slower cars mean more actual hours driven which means more smog which will drive the EcoFreaks up a wall. The will continue to spout their global warming nonsense of course but they'll call for extra taxes to compenste for the additional pollution.
These are just a few of the things I can think of at the moment. Any other ideas?