In 1987 the federal government permitted states to raise the speed limit on their rural interstate roads, but not on their urban interstate roads, from 55 mph to 65 mph for the first time in over a decade. Since the states that adopted the higher speed limit must have valued the travel hours...

This study estimates the dose-response relationship between Body Mass Index (BMI) and crash risk in commercial motor vehicle operators. Intake data was collected on 744 new truck drivers who were training for their commercial driver's licenses at a school operated by the cooperating trucking...

To date, 16 states have passed medical marijuana laws, yet very little is known about their effects. Using state-level data, we examine the relationship between medical marijuana laws and a variety of outcomes. Legalization of medical marijuana is associated with increased use of marijuana among...

The Office of National Drug Control Policy (ONDCP) recently announced a goal of reducing drugged driving by 10 percent within three years. In an effort to achieve this goal, ONDCP is encouraging all states to adopt per se drugged driving laws, which make it illegal to operate a motor vehicle...

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...

This paper assesses the effectiveness of child safety seat laws. These laws progressively increased the mandatory age up to which children must be restrained in safety seats in cars. We use US Fatality Analysis Reporting System (FARS) data from 1978 to 2011 and rich state-time level variation in...