Costs and Benefits of Strategic acquisition of Limited Access Right-of-Way at Freeway Interchange Areas

Past research shows that access connections and signalized intersections within the functional area of an interchange can adversely impact safety and operations at the interchange and on the freeway. A variety of transportation problems occur when driveways and intersections are too close to interchange ramps. Signalized intersections too close to ramp termini can cause heavy volumes of weaving traffic, complex traffic signal operations, accidents, congestion, and traffic backing up the ramps on to the main line (1). Curb cuts and median openings near the ramp termini further compound these problems. It follows, therefore, that avoiding access in the functional area of freeway interchanges through effective planning and access control will help to preserve traffic safety and operations and may eliminate or postpone the need for interchange improvements. Alternatively, access in the functional area of a freeway interchange could shorten the functional life of the interchange and lead to serious safety and operational problems on the mainline. Although controlling access in the functional area of interchanges does have obvious safety and operational benefits, the cost-effectiveness of strategically acquiring additional limited access right of way for this purpose has not been examined. Is it cheaper, for example, to spend more of our limited transportation dollars on limited access right-of-way at the time an interchange is built, than to continue with current right of way acquisition practices? Would acquiring more access control in the vicinity of interchanges significantly postpone or avoid the need for interchange reconstruction? If so, will the up-front cost of acquiring more access control, be outweighed by the benefits of not having to reconstruct the interchange sooner than planned? And what are the safety implications if interchange area access is not effectively managed? The Center for Urban Transportation Research (CUTR), under a grant from the Florida Department of Transportation (FDOT), is examining these important policy questions. The primary objective of the study is to assess the cost effectiveness of purchasing additional limited access right-of-way at the time of construction in lieu of retrofitting interchange areas after functional failure. The study is particularly important given the rapid growth and dramatic increase in right-of-way costs that has been observed in Florida over the past few decades. + Read more