Vehicles under about 10,000 pounds cause the same level of pavement damage. These include passenger cars, pickups, and SUVs. Vehicles more than 10,000 pounds cause more damage that increases with weight. Those vehicles pay diesel taxes and weight taxes for road maintenance. The RUC research is focusing on passenger vehicles weighing less than 10,000 pounds because this vehicle category is quickly growing more fuel-efficient and eroding gas tax revenue.