Right turn split: A new design to alleviate weaving on arterial streets

While weaving maneuvers occur on every type of roadway, most studies have focused on freeway maneuvers. Weaving occurring on non-freeway facilities, such as arterial streets, can cause significant operational problems. Arterial streets weaving typically occur when vehicles coming from a side street at an upstream intersection attempt to enter the main street from one side to reach access points on the opposite site at a downstream intersection by crossing one or more lanes. The freeway methodology to deal with weaving may not applicable to arterial streets since arterials streets, unlike the freeways, tend to have shorter weaving lengths and lower speeds. This dissertation investigates the types of weaving movements occurring between two closed-spaced intersections on an arterial street, presents the type of problems occurring due to the weaving movements, and recommends a new design to alleviate weaving on arterial streets.; Firstly, the dissertation examined the different weaving movements occurring between two close-spaced intersections in two sites in Florida. The two sites had a heavy right turn volume entering from the side street and close-spaced intersections. The dissertation also explained the breakdown conditions caused by the weaving movements at the two sites. Secondly, the dissertation proposed a new design, Right Turn Split (RTS), to alleviate the operational problems caused by the weaving movements on arterial streets. The new design proposed separating the worst weaving movement entering the arterial from the other movements and providing a separate path for this movement to alleviate the delay on the arterial street. The new method is easy to implement and does not require much right of way.; Thirdly, the dissertation compared two microscopic models, SimTraffic and VISSIM, to choose the most suitable model to be used to study the operational benefits of the RTS design on the delay of the arterial street. Based on the results of the comparison, it was decided to use SimTraffic for the analysis due to the many features in intersection's coding and data entry. Fourthly, the dissertation proposed a new calibration and validation procedure for microscopic simulation models that focused on arterial streets. The procedure was applied on SimTraffic using the traffic data from the two studied sites in Florida. The proposed procedure appeared to be properly calibrating and validating the SimTraffic simulation model.; Finally, the calibrated and validated model was used to study the operational benefits of the proposed design. Using a wide range of geometric and volume conditions, 1,458 SimTraffic models, 729 before and after pairs, were created to compare the delay of similar scenarios before and after applying the RTS design. The results were analyzed graphically and statistically. The findings of the analysis showed that, for the geometric and volume conditions tested, the proposed design provided lower delay on the arterial street than the original conditions, which concludes that the RTS design provided a delay reduction.