Data from the AASHO Road Test and other field experience indicate that most pavement distress and damage are associated with heavy axle loads from highway vehicles. Specifically, the Road Test data show that pavement damage increases exponentially as axle loads get heavier. Analysis of the Road Test Data also indicates that increases in pavement thickness permit exponential increases in equivalent axle loads for comparable pavement performance. Mr. F. C. Turner, retired FHWA Administrator, suggested that use of longer trucks with more axles and lower axle loads could result in reduced damage to pavements and more efficient use of transportation funds.

This is a very complex issue involving technical, economic, social, and other factors. No detailed systematic evaluation had been made of the influence of vehicle configurations (e.g., axle loads, axle spacing, tire pressures, and spring components) and highway design (e.g., pavement thickness, bridges and geometrics) on the efficiency of the highway transportation system.

The overall objective of this project was to develop recommendations for coordination of heavy vehicle configurations and pavement, bridge, and highway geometric design to produce the most practical and efficient transportation of goods and services over the highway system.

Research on all major objectives has been completed.

The final report has been published as TRB Special Report 227, New Trucks for Greater Productivity and Less Road Wear---An Evaluation of the Turner Proposal."