Auto pollution and congestion in an urban model: An analysis of alternative strategies

Congestion and pollution externalities associated with automobile driving are examined for their effect on urban structure. A monocentric urban model which incorporates household preferences for both an unpolluted environment and for leisure time is presented, and used to evaluate alternative pricing and emissions policies on automobile use and their effects on city structure. Optimal tax gradients for driving are derived, and compared with second best cases of per mile taxes and no taxes. As externalities gradients become more nonlinear, the welfare gains from employing optimal taxes rather than a per mile tax are increased. The appropriate choices of an emission standard, highway capacity, and highway pricing policy must be made simultaneously and depend on household preferences.