Mathematical analysis of trucks blocking roadway signs

The problem of obstructed road signs is significant because a missed sign c an lead to driver confusion and, consequently, safety hazards. One of the m ain instances when drivers experience blocked road signs is when a passenge r car in the left lane has their field of vision obstructed due to the pres ence of a large truck in the right lane. Despite the significance of the pr oblem, little research has been done to quantify obstruction of road signs. This paper develops a mathematical model that estimates the probability th at a vehicle in the left lane misses a road sign due to a large truck in th e right lane. A sensitivity analysis is then performed, and it is found tha t 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 advan tages and disadvantages of each alterative are discussed. The alternatives are constructing higher signs, using overhead signs, repeating road signs, putting signs on both sides of a roadway, changing traffic patterns, and us ing Intelligent Transportation Systems instrumentation to decrease the numb er of signs that are missed by drivers. The paper also includes a section o n the real-life field verification and validation of the developed mathemat ical model.