The objective of this study was to develop practical procedures that more accurately reflect the actual fatigue conditions in steel bridges, and that can be applied for evaluation of existing bridges or design of new bridges. The procedures were intended to permit determination of fatigue-load ratings and estimation of remaining fatigue life for existing bridges.

Research has been completed and the final report published as: NCHRP Report 299, "Fatigue Evaluation Procedures for Steel Bridges." The report provides recommended revisions to the fatigue evaluation requirements in the AASHTO Manual for Maintenance Inspection of Bridges, and to the design requirements in the AASHTO Standard Specifications for Highway Bridges.

The recommended fatigue design provisions were adopted by AASHTO in 1988 and issued in 1989 as the AASHTO Guide Specifications for Fatigue Design of Steel Bridges. The recommended fatigue evaluation and remaining life estimation guidelines were adopted by AASHTO in 1989 and were issued as the AASHTO Guide Specification for Fatigue Evaluation of Existing Steel Bridges.