A two-wheeled skid-test trailer and towing vehicle were acquired in 1969. The trailer was designed primarily for measurement of steady-state friction at and above normal traffic speeds. Measurement of instantaneous wheel loads also permitted determination of peak or incipient friction. Factors and variables associated with the testing device and calibration and test procedures were investigated and standardized, and the trailer was adopted for routine testing. Comparative tests with the trailers of General Motors, Ohio, and West Virginia were conducted, and the data were correlated. The interim standard method of test using an automobile was correlated with the trailer to permit conversion of data accumulated in preceding years.

Report Date


Report Number

No. 338

Digital Object Identifier



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