Safety Analysis of Florida Urban Limited Access Highways with Special Focus on the Influence of Truck Lane Restriction Policy

Detailed modeling of traffic crashes occurring on urban limited access highways in Florida was conducted to determine the influence of various geometric and traffic variables on crash occurrence with special emphasis on presence of truck lane restriction. The geometric variables modeled were length of each segment, number of lanes, number of interchanges, number of ramps, lane width, and shoulder width. The traffic variables modeled were average annual daily traffic, percent of trucks, operating speeds, presence of high occupancy vehicle lane, and presence of truck lane restriction lanes. Also included in the modeling were variables accounting for differences in driving behavior in different urban regions of the State of Florida. The results showed that, although statistically insignificant (p<=0.808), the presence of truck lane restriction had a negative modeling coefficient suggesting that sections with truck lane restriction tended to have less crashes than sections without truck lane restriction. This tendency was confirmed with a marginal effect analysis which showed that implementing truck lane restriction on a Florida urban freeway would have an annual effect of reducing crashes by approximately 4%. These results are in line with the results reported in a number of previous studies investigating the efficacy of truck lane restriction. In addition, various modeling paradigms revealed that there were regional differences in crash occurrence in which the probability of crash occurrence increased from the Orlando area, the Jacksonville area, the Tampa area, the to tricounty area of Palm Beach, Broward, and Miami-Dade, in that order.