Highway Spending and Induced Vehicle Emissions: Evidence from the US states

This paper investigates the impact of state and local government highway spending on vehicle emissions. A theoretical framework is constructed to show the effect of government highway spending on passenger and freight vehicle emissions and decompose the effect into a rebound effect, an induced demand effect and an interaction effect. We then develop an empirical strategy and combine state-level data in the US to test the induced CO2 emissions by government highway spending. We find that there are positive and significant total effects of government highway spending on passenger and freight vehicle emissions. The magnitude of these effects, however, significantly differs from one another as the elasticity of freight vehicle emissions with respect to government highway spending is four times larger than that in the passenger sector. The difference can be plausibly explained by the rebound effect and the interaction effect. We argue that policies regarding government spending on highway projects, especially those relying on cost-benefit analysis, should account for the potential difference in induced environmental impacts between passenger and freight vehicles.