But so too would it be a good idea to discourage driving through higher tolls, pricier gas, and better public transportation.
Expanding public transportation may be a good solution to the rising costs of driving personal vehicles. 
mnli hypothesis: Expanding public transportation may be a good solution to the rising costs of driving personal vehicles.  premise: But so too would it be a good idea to discourage driving through higher tolls, pricier gas, and better public transportation.