In cities worldwide, the widespread use of single occupancy cars often leads to traffic congestion and its associated ill effects. Using high frequency data from Google Maps, we test whether high-occupancy vehicle (HOV) policies can be an effective tool to combat congestion. Using the unexpected...

Will politics lead to over-building or under-building of transportation projects? In this paper, we develop a model of infrastructure policy in which politicians overdo things that have hidden costs and underperform tasks whose costs voters readily perceive. Consequently, national funding of...

We assemble a new global database on motor vehicle travel speed in over 1,200 large cities in 152 countries. We then estimate comparable city-level indices of travel speed and congestion. Most of the variation in urban travel speed is across countries, not within. National income per capita...

We use data from Reserve Bank of India to study the impact of India's Golden Quadrilateral (GQ) highway project on finance-dependent activity. Loan volumes increase by 20-30% in districts along GQ and are stronger in industries more dependent upon external finance. Loan growth begins with...

We develop a general equilibrium geographic framework to characterize the welfare effect of transportation infrastructure investments. We tackle three distinct but conflating challenges: First, we offer an analytical characterization of the routing problem and, in particular, how infrastructure...

Previous work on transportation investments has focused on average impacts in high- and middle-income countries. We estimate average and heterogeneous effects in a poor continent, Africa, using roads and cities data spanning 50 years in 39 countries. Using changes in market access due to distant...

What is the impact on intra-national trade and regional economic outcomes when the quality and lane-capacity of an existing paved road network is expanded significantly? We investigate this question for the case of Turkey, which undertook a large-scale public investment in roads during the...

The importance of increments to an existing highway system depends upon their contributions to the accessibility provided by the existing network. Nearly 40 years ago, Mohring [1965] suggested this logic for planning optimal highway investment programs. He argued it could be implemented by...

We investigate the relationship between interstate highways and highway vehicle kilometers traveled (VKT) in US cities. We find that VKT increases proportionately to highways and identify three important sources for this extra VKT: an increase in driving by current residents; an increase in...