Judgment of speed has long been a matter of interest to students of highway safety. Forbes (1) early devised an apparatus which was used in the laboratory for measuring judgment of speed in the longitudinal direction. His apparatus consisted of a long roadway on which metal tape carried small cars. A control car was allowed to travel in traffic on the right side of the road. At such times as there was danger of a collision the operator was required to turn sharply in order to avoid colliding with another vehicle. The number of times that he failed to dodge in time to avoid a collision was recorded electrically. Essentially it was comparable to having subjects riding in one car judge at what point they would meet an oncoming vehicle.
Proceedings of the Iowa Academy of Science
©1957 Iowa Academy of Science, Inc.
Suhr, Virtus W.
"Comparison of Laboratory and Field Studies in the Estimation of Driving Speed,"
Proceedings of the Iowa Academy of Science, 64(1), 546-552.
Available at: https://scholarworks.uni.edu/pias/vol64/iss1/65