The effects of added transportation capacity. Conference proceedings.

Transportation Department, Washington, D.C.

Effects of recent vehicle design changes on safety performance. Volume II: interim report.

National Highway Traffic Safety Administration, Washington, D.C.

Truck weight effects on bridge costs. Final report.

Ohio Department of Transportation, Columbus

An evaluation of the effects of glass-plastic windshield glazing in passenger cars.

Mode of access: Internet.

The simulation of vehicle dynamic effects on road pavements /

"November 1992."

Age effects on symbol sign recognition /

Mode of access: Internet.

Effects of short term oven aging on volumetrics and selection of N-design /

"Study was conducted in cooperation with the U.S. Department of Transportation, Federal Highway Administration."

Effects of highways on wildlife populations and habitats : phase 1, selection and evaluation of procedures /

Mode of access: Internet.

Research on the effects of urbanization on small stream flow quality /

Mode of access: Internet.

A simulator study of the combined effects of alcohol and marihuana on driving behavior. Phase II. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Effects of taper length on traffic operations in construction zones /

Final report; December 1977.

Effects on flexible highways of increased legal vehicle weights using VESYS IIM, final report /

Mode of access: Internet.

Dynamic Behavior and Fatigue Life of Highway Bridges Due to Doubling Heavy Vehicles

An increase in the demand for the freight shipping in the United States has been predicted for the near future and Longer Combination Vehicles (LCVs), which can carry more loads in each trip, seem like a good solution for the problem. Currently, utilizing LCVs is not permitted in most states of the US and little research has been conducted on the effects of these heavy vehicles on the roads and bridges. In this research, efforts are made to study these effects by comparing the dynamic and fatigue effects of LCVs with more common trucks. Ten Steel and prestressed concrete bridges with span lengths ranging from 30’ to 140’ are designed and modeled using the grid system in MATLAB. Additionally, three more real bridges including two single span simply supported steel bridges and a three span continuous steel bridge are modeled using the same MATLAB code. The equations of motion of three LCVs as well as eight other trucks are derived and these vehicles are subjected to different road surface conditions and bumps on the roads and the designed and real bridges. By forming the bridge equations of motion using the mass, stiffness and damping matrices and considering the interaction between the truck and the bridge, the differential equations are solved using the ODE solver in MATLAB and the results of the forces in tires as well as the deflections and moments in the bridge members are obtained. The results of this study show that for most of the bridges, LCVs result in the smallest values of Dynamic Amplification Factor (DAF) whereas the Single Unit Trucks cause the highest values of DAF when traveling on the bridges. Also in most cases, the values of DAF are observed to be smaller than the 33% threshold suggested by the design code. Additionally, fatigue analysis of the bridges in this study confirms that by replacing the current truck traffic with higher capacity LCVs, in most cases, the remaining fatigue life of the bridge is only slightly decreased which means that taking advantage of these larger vehicles can be a viable option for decision makers.