Testing for low-speed skid resistance of road pavements

Low-speed skid resistance tests provide useful information not available from the normal high-speed skid resistance testing of road pavements. There are known limitations of the two commonly used measuring devices of low-speed skid resistance, i.e. British Pendulum Tester (BPT) and Dynamic Friction Tester (DFT). This study develops a Walking Friction Tester (WFT) to offer a practical alternative to measure low-speed pavement skid resistance. This paper compares WFT with BPT and DFT measurements in the following three aspects: correlation relationship, measurement variability, and speed comparison of field tests. Tests were also performed to examine the variability of WFT test results with respect to walking speed and water film thickness, respectively. The study showed that there was a good correlation coefficient of 0.80 between BPT and WFT measured data, and 0.70 between DFT and WFT friction coefficients. WFT measured data were found to have smaller variability than those of BPT and DFT. In field tests performed over a length of pavement section, WFT generated continuous friction data in much shorter times compared with the spot measurement mode of either BPT or DFT. The results also showed that WFT tests were independent of changes in walking speeds of operators and variations of water film thickness applied.