Two-Sided Weaving Analysis on One-Way Frontage Roads (1393-2)

Over the past few years, there have been many studies concerning the effects of weaving on freeway operations; however, there have been few attempts to study the effects of weaving at "non-freeway" sites, such as freeway frontage roads. As part of a larger study that is developing a level of service evalution procedure for freeway frontage roads, this report addresses the issues associated with two-sided weaving on one-way frontage roads (between an exit ramp and a downstream signalized intersection). The objectives of this study were to develop a technique for evaluting two-sided weaving operations, and to develop recommendations on minimum and desirable ramp-to-intersection spacing. To meet these objectives, both field data and computer simulation were used. As a result of this study, the following three levels of service were defined based upon frontage road density between the exit ramp and downstream intersection: unconstrained (density < 40 veh/km/ln), constrained (density from 40-100 veh/km/ln), and undersirable (density > 100 veh/km/ln). Recommended ramp-to-intersection spacings were developed based on frontage road volume, exit ramp volume, and percent exit ramp vehicles making a two-sided weaving maneuver.