EXPERIMENTS that have been in progress since the 1929 Semi-Annual Meeting to measure the fatigue caused by an automobile ride, using the human body as a measuring instrument, and to predict there-from the possible effects of various types of spring-suspension, shock-absorber and other comfort-giving components are described. Initially, the problem was approached from the physiological standpoint because fatigue is definitely known to be a physiological phenomenon and, if the physiological changes are sufficiently marked to be measured, physiological tests are definite and quantitative.
Changes in the human body are a good index of relative comfort, and, if the normal reactions of an individual or any group of individuals before a test are known, similar measurements at the end of a test or at the end of an automobile ride should show an appreciable difference. This difference, which the author claims is a direct measure of comfort, can be determined by measuring physical and nervous fatigue. For measuring the latter, number checking, speed of reaction, mental multiplication, steadiness of the hand and basal-metabolism rate tests were given; and, for the former, equilibrium tests using a wabblemeter were employed. Descriptions of various types of wabblemeter are included, and the results of the nervous-fatigue tests are presented.
Plans for future development and study include (a) further improvement and standardization of two types of wabblemeter, (b) further standardization of the basal-metabolism test with particular attention to establishing a normal for different times of day, (c) improvement of the score card for reporting discomfort after the riding tests and (d) experiments with other new measuring devices. Further experimentation will include (a) investigation and application of tests to subjects in the laboratory, (b) study of tests on a large number of taxicab and motorcoach drivers and (c) application of the results with various outside groups of riders and test persons.
In the discussion* the extraordinary importance and great value of the investigation was stressed. Much work remains to be done, according to the various speakers, some of whom suggested future tests.