This report presents an analysis of HOV improvements for two signalized arterials in the Seattle metropolitan area. The first involves a planned 1,000 foot (300 meter) queue jumper lane on NE Pacific Street in the University District of Seattle. This planned improvement was studied prior to its implementation in Spring 1990. As part of this study, an extensive before-data set was developed. The planned improvement is now in place, and an extensive after-study is now in progress as part of a follow-up project. The second study was more of a feasibility analysis of possible HOV improvements for a suburban arterial. Specifically, NE 85th/Redmond Way, an arterial that stretches 2.5 miles (4 km), from Interstate 405 in Kirkland to Willows Road in Redmond, was identified as one of the highest priority candidates for arterial HOV improvements.
Because of limited arterial HOV experience in Seattle and nationwide, the study of these two very different types of HOV arterial improvements provided important information for future arterial plans. This project investigated HOV improvements for arterials in the Seattle area, simulated the operation of those improvements for the two case studies, developed a data set for evaluating the impacts of the improvements, and carried out some preliminary evaluations.
The preliminary findings of these two case studies suggested favorable outcomes for the planned HOV improvements. Keeping in mind that these analyses must be evaluated in the context of the surrounding network, the results of these two studies are optimistic.