Summer is over and people are back to commuting to work and school along Issaquah Hobart. King County Road Services (Roads) has been actively monitoring traffic on this corridor during peak commute times since the County restricted right turns from Issaquah Hobart Road SE onto SE Tiger Mountain Road between 6-8 a.m. last April.
Since the right turn restriction took effect, Roads has observed decreased traffic volumes on SE Tiger Mountain Road and less zippering of vehicles further north where SE Tiger Mountain Road rejoins Issaquah Hobart Road SE during the morning commute. This is an indication that the right turn restriction is working.
The right turn restriction was implemented to address safety challenges created as increased congestion on the Issaquah Hobart corridor resulted in drivers using Tiger Mountain Road as a bypass. Issaquah Hobart Road is classified as an Urban Principal Arterial roadway and is designed to provide for movement across and between larger urban regions for through traffic. In contrast, Tiger Mountain Road is classified as an Urban Local Road, which means it was designed to serve local neighborhood traffic volumes and slower speeds.
High volumes of vehicles moving at higher speeds on Tiger Mountain, trying to shorten their commutes by jumping the queue on Issaquah Hobart, created safety issues for all drivers and this neighborhood. Additionally, traffic was slowing and disrupted again where cars rejoined the queue on Issaquah Hobart.
The right turn restriction does not and will not reduce the number of vehicles traveling northbound on Issaquah Hobart during the morning commute. The vehicles that were attempting to use Tiger Mountain Road to skip ahead of congestion on Issaquah Hobart, many of which were travelling at faster than the posted 35 MPH speed limit, still rejoined Issaquah Hobart further north backing up traffic at other intersections in the process. You can do your part to reduce congestion along Issaquah Hobart by joining a carpool, Vanpool, or Rideshare. You can also better time your commute in the morning by checking our real-time traffic cameras at the intersection of Issaquah Hobart Road SE and Cedar Grove or Issaquah Hobart Road SE and May Valley Road to check congestion before you leave.
Several county roadways, including Issaquah Hobart Road SE and SE Tiger Mountain Road, are at or near their capacity for carrying traffic, resulting in the congestion people experience today. Unfortunately, the County does not have enough funding to expand the capacity of Issaquah Hobart Road, and expansion of Tiger Mountain Road would not be feasible even if funding were available. The County will continue to address critical safety issues and perform maintenance on this road. Learn more.
Still, lower-cost solutions to help ease congestion along Issaquah Hobart Road SE and SE Tiger Mountain Road have been ongoing. We are focusing on safety and maintenance that will maximize traffic flow on the existing road network and direct traffic.
King County is partnering with the City of Issaquah to conduct a corridor analysis of this area. This study will help identify potential improvements for the unincorporated King County intersections as well as intersections further north within the City of Issaquah’s jurisdiction. We expect the study to begin next year.