摘要: |
In September 1963, J. E. Meyer submitted proposed Supplemental Specifications for Rubber Pads for Railroad Crossings (dated July 25, 1963) and Standard Plan E-4-A-146 Rubber Pad Railroad Crossing Installation (dated September 6, 193) to the Bureau of Public Roads for approval. The Research Laboratory Division of the Office of Testing and Research was assigned the responsibility of conducting material tests, as well as performing field evaluation tests on the two types of crossings. A field test program was designed to evaluate each of the four factors under study and consisted of the following: (1) durability; (2) riding quality; (3) skid resistance, and (4) safety. |