Grade Severity Rating System (GSRS). Users Manual

摘要

The grade severity rating system (GSRS) reduces the probability of large truck runaways on severe downgrades. It is based on a mathematical model that uses gross truck weight and physical characteristic of the downgrade to predict the temperature of the truck's system brakes. The brake temperature estimates are used to determine maximum safe descent speeds for different categories of truck weight. The maximum safe descent speed information is presented to the truck drivers by weight specific speed signs (WSS) installed at the downgrade site. The users manual presents the procedural steps and analysis activities required to select appropriate downgrades, determine the safe downgrade speeds and install the WSS signs. Determination of the safe downgrade speeds is accomplished by the use of the GSRS computer program, developed as a part of the project. The program, developed for use on IBM PCs and compatibles, has applications in addition to determining safe truck downgrade speeds. The additional applications include determining grade severity, establishing downhill truck speed limits, establishing the need for; and location of truck escape ramps and analyzing truck accidents.