Offering an examination of the relationship between congestion tolls and highway capacity in the long run, this study breaks new ground in the economic theory of optimal road capacity by including theoretical contributions, empirical studies, and simulation experiments that all pertain to the general topic reflected in the title. The book is organized into four sections: 1) highway traffic flow; 2) commuter choice of tollways versus freeways; 3) congestion pricing in the short run; and 4) road capacity and pricing in the long run. In particular, the first section on highway traffic flow examines the chief models and empirical studies of vehicular flow on urban highways. The second section of the book is a theoretical and empirical examination of the choice that commuters make between urban tollways and freeways. The third section is devoted to congestion pricing in the short run, the time period in which the urban highway facilities are taken as given. This section is the most important part of the book from the standpoint of public policy. The fourth and last section of the book considers road capacity and pricing in the long run, with the concluding chapter gathering the authors’ main results in one place and making recommendations both for current policy and for future research.