Why can solo vehicles use the HOV Reversible Express Lanes on I-90 in some places?
Single occupant vehicles traveling between Seattle and Mercer Island are allowed to use the I-90 HOV Reversible Express Lanes. Solo drivers may use the lanes between Rainier Avenue S and Island Crest Way (Exits #3 and #7) in the center roadway in both directions. Solo drivers cannot use the HOV Reversible Express Lanes east of Island Crest Way on Mercer Island or west of Rainier Avenue S. They also cannot use the new HOV segment between south Bellevue and Mercer Island on the westbound mainline outer roadway, nor the direct access ramps serving it. The allowance of single occupant vehicles on certain parts of the I-90 HOV Reversible Express Lanes stems from a 1976 Memorandum of Agreement which identified how I-90 would be operated. The memorandum recognized that the Reversible Express Lanes might someday become overloaded and therefore established a hierarchy of users. It identified buses as having the highest priority, followed by other HOVs, and then vehicles going to and from Mercer
