• Printable travel time/ reliability data (pdf 165 kb)

• Northbound the HOV lane provides a travel time advantage throughout the day from approximately 4:30 AM to nearly 7:00 PM. The travel time savings are greatest in the morning peak and decrease in the midday.

• Both the HOV lane and the general purpose lanes experience significant slowing in the morning peak period. Some of this congestion is caused by backups at the entrance to the express lanes in downtown Seattle. HOV lane speed and reliability fall below the state standard for about an hour and a half on average during the morning peak period.



• Southbound the HOV lane provides a travel time advantage, though it is much less than in the northbound HOV lane. Average HOV travel time savings are only about 2 minutes in the PM peak. As the graph shows, this is largely due to slowing in the HOV lane.

• In the southbound direction, HOV lane speed and reliability frequently fail to meet the state standard. Average vehicle speed in the HOV lane slows to less than 45 mph more than half the time. Much of this slowing is associated with the steep grade up the Southcenter Hill and merge activity at the I-405 interchange. In off-peak hours the lane performs with a high degree of speed and reliability.