The paper describes an interactive and simple queuing model developed to evaluate potential delays to both vehicular and vessel traffic caused by openings and closures of a draw bridge. The queuing procedures were developed to evaluate the proposed replacement alternatives (ie, fixed-span bridge, tunnel or moveable bridge with 55 ft (16.77 m) vertical clearance) to the existing SE 17th Street draw bridge across the lntracoastal Waterway (ICWW) in Ft. Lauderdale, Florida. Currently, excessive delays are experienced by vehicular and vessel traffic using the SE 17th Street draw bridge and the ICWW, respectively. Queues to both the vehicular and vessel traffic were estimated and analyzed using a variety of factors ranging from bridge operating characteristics and available boat holding capacity in the ICWW to forecasted vehicle and vessel traffic. The queuing procedures are demonstrated in the paper mostly via examples for the sake of simplicity in presentation. The queuing procedures presented in the paper provided useful information, such as hours of delay to vessel and vehicular traffic, which was used to evaluate the proposed replacement facilities. The queuing analysis also provided useful and appropriate guidance for changing the historical 15-min bridge opening cycle to a 30-min time-saving bridge opening scheme.

An interactive and simple queuing model developed to evaluate potential delays to both vehicular and vessel traffic caused by openings and closures of a draw bridge is described in this paper. Necessary data for the empirical analyses were collected in relation to operation of the existing SE 17th Street draw bridge across the Intracoastal Waterway (ICWW) in Ft. Lauderdale, Florida. The existing bascule bridge provides 25 ft (7.62 m) of vertical clearance and it is located between two signalized intersections that are less than 1 mi (1.67 km) apart. Because of the excessive delays to both vessel and vehicular traffic, the Florida Department of Transportation (FDOT) has embarked on evaluation of the following alternatives for replacement of the existing draw bridge:(a) a high-level, fixed-span bridge;(b) a tunnel; and (c) a higher-level, moveable bridge.