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...

The presence of a heavy truck on the road can impose an externality if accidents occur that would not have otherwise. We find each additional truck on the road increases the risk of a truck accident--but also, at an even higher rate, the risk of a car-on-car collision. Our estimates imply two...

Developing country megacities suffer from severe road traffic congestion, yet the level of congestion is not a direct measure of equilibrium inefficiency. I study the peak-hour traffic congestion equilibrium in Bangalore. To measure travel preferences, I use a model of departure time choice to...

I assess the efficiency of transport networks for every country in Africa. Using rich spatial data, I simulate trade flows over more than 70,000 links covering the entire continent. I maximise over the space of networks and find the optimal road system for every African state. My simulations...

We exploit arguably exogenous train schedule changes in Washington DC to investigate the relationship between public transportation provision, the risky decision to consume alcohol, and the criminal decision to engage in alcohol-impaired driving. Using a triple differences strategy, we provide...

We exploit the introduction of electronic toll collection, (E-ZPass), which greatly reduced both traffic congestion and vehicle emissions near highway toll plazas. We show that the introduction of E-ZPass reduced prematurity and low birth weight among mothers within 2km of a toll plaza by 10.8%...