Author Description

This study established the unit costs of pavement and bridge damage due to overweight vehicles, and discussed issues concerning overweight vehicle e enforcement in Indiana. The study identified gaps in the existing practice and research, and established a practical framework that includes the development of asset families; establishment of realistic types and timings of reconstruction, rehabilitation, and maintenance, traffic volumes and growth projections; and damage cost estimation for each asset family and age group. The sensitivity of asset damage cost with respect to key policy and analysis variables was explored. Finally, the study examined the cost and operational issues associated with the enforcement of overweight truck policies. For pavement assets, the damage cost estimates were found to range from $0.006 per ESAL-mile on Interstates to $0.218 per ESAL-mile on non-national highways. The results also suggested that the pavement damage cost estimates are highly sensitive to the pavement life-cycle length, interest rate, rest period, and the costs and service lives of rehabilitation treatments. For bridges, an incremental-design methodology was used to assign damage cost to vehicle classes based on axle configurations and vehicle-miles of travel. Each FHWA vehicle weight group was classified into an equivalent AASHTO loading using the modified equivalent vehicle model which is based on gross vehicle weight, axle loading and axle spacing. Adopting a permit structure on the basis of gross vehicle weight only, will result in some vehicles underpaying by as much as 92% of their actual contribution to bridge damage. Finally, the study examined the cost and operational issues associated with the enforcement of overweight truck policies and made recommendations regarding equipment types and locations, staffing, and staff schedules, in order to promote cost-effective practices in weight enforcement.