MATHEMATICAL ANALYSIS OF TRUCKS BLOCKING ROADWAY SIGNS

Abstract

The problem of obstructed road signs is significant because a missed sign can lead to driver confusion and, consequently, safety hazards. One of the main instances when drivers experience blocked road signs is when a passenger car in the left lane has their field of vision obstructed due to the presence of a large truck in the right lane. Despite the significance of the problem, little research has been done to quantify obstruction of road signs. This paper develops a mathematical model that estimates the probability that a vehicle in the left lane misses a road sign due to a large truck in the right lane. A sensitivity analysis is then performed, and it is found that the volume of trucks is the most important parameter in whether or not a sign will be obstructed long enough so that the driver of a vehicle in the right lane misses the sign. After the sensitivity analysis, six alternative solutions to the problem of blocked road signs are detailed, and the advantages and disadvantages of each alternative are discussed. The alternatives are con structing higher signs, using overhead signs, repeating road signs, putting signs on both sides of a roadway, changing traffic patterns, and using Intelligent Transportation Sys tems instrumentation to decrease the number of signs that are missed by drivers. The paper also includes a section on the real-life field verification and validation of the developed mathematical model.