A literature study was carried out concerning the effects of vibration on man. The results showed that vibration resulting from road roughness could very well have a negative effect on the driver's performance and alertness. A simulation experiment in a film simulator was also carried out in which 30 male and female subjects were exposed to vibrations of varying frequency and amplitude similar to those experienced on an actual road. The vibrations given to the subjects are what man stands 2 hours according to ISO 2631 whole body vibration standard without performance deficiency. The subjects were seated in the front half of a passenger car and the driving tasks were designed to be similar to those encountered during real driving conditions. The subjects were divided into three groups and measurement was carried out during pre-trial (20 min), trial (120 min), and post-trial (40 min) phases. During the trial phase, two of the three groups were exposed to high amplitude vibrations (one to low-frequency and the other to high-frequency vibrations) and in the post-trial phase of the experiment, all three groups were exposed to low amplitude vibrations similar to those experienced on a very smooth road. The results indicated that high amplitude stochastic vibrations (road roughness) affect a driver's performance and alertness both during the occurrence of the vibration as well as afterwards.
Abstract