Abstract
The objective of this research effort was to determine on the basis of driver performance the distance, upstream of the exit gore point, at which an exit direction sign should be located on a freeway or interstate facility. The distance was expected to vary with a number of situational variables, several of which were investigated in this research. To determine the placement distance a model was developed relating the various components of the exiting process to the sign placement distance. These various components are: sign reading distance, decision distance, lane maneuvering distance, and declaration distance. In terms of the model, the best estimate of sign placement distance is equal to the sum of the decision distance, lane maneuvering distance, and declaration distance minus sign reading distance. To obtain actual freeway distances associated with components of the model an instrumented vehicle study was performed. Twenty drivers from Houston, Teas, drove sections of two freeways near downtown Houston. One freeway (I-45) was used for the lane maneuvering study. All drivers were required to drive a three and four-lane section of the freeway and maneuver from the extreme right lane in light, medium and heavy traffic conditions. To determine an estimate of maneuvering distance, each driver was required (as by instructions) to perform in succession three-lane change maneuvers on both the three and four-lane sections in each of the three traffic volumes..
McNees, Roger Wayne (1976). The determination of the advanced sign placement distance based on a human factors evaluation of the exiting process. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -473593.