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CHAPTER l: INTRODUCTION volumes are approximately four times higher 1,000 vehicles per hour. On Memorial Day,the on 1-90 and three times higher on county hourly volumes exceeded 2,500 vehicles per roads than typical days. Speeds drop from an hour for 12 hours and the total daily demand is average of 70 miles per hour(mph)to 15 mph almost three times higher. on 1-90, and increase by approximately 5 mph Although this 2019 study focused on traffic on county roads, reflecting that non-local between MP 70 and MP 93, the modeling travelers tend to speed along the local roads results indicated major congestion resulted as they avoid 1-90 congestion. On those specific from traffic entering at MP 80. Therefore, Mondays, congestion lasts for 12 hours on this feasibility study addresses these traffic 1-90, while diversion and increased speed lasts challenges by developing and analyzing approximately 6 hours on the county roads. potential alternative solutions between MP 70 The study also found the average travel speed and MP 85. along 1-90 within the study area, at 1:00 pm on Memorial Day 2018, was less than 20 mph. Based on the historical speed data,there is 1.3 Study Partners congestion along the corridor between 10:00 In conducting this study,the County's priority am and 9:00 pm.Travel speeds increased past was to coordinate with a broad range of groups MP 70 (traveling westbound)where the freeway who utilize or operate the transportation widens from two to three lanes. network within the study area.A key element Compared with typical volumes on I-90 (mid- of this effort included partnering with WSDOT week during the fall and spring months),the to confirm proposed alternatives align with volumes on summer and holiday weekends the State's goals and plans. Since I-90 is a were significantly higher. On an average federal(Federal Highway Administration, weekday,the hourly volume never exceeded FHWA)facility operated by WSDOT, it is •- } - VOLUME I: FEASIBILITY REPORT 1-90 Corridor Easton to Cle Elum Feasibility Study 1 4