I-90 interchanges to see major changes
September 23, 2008
By Jon Savelle
The I-90 Corridor Study, an ongoing effort by the state Department of Transportation to find solutions to congestion and safety problems between Bellevue and North Bend, is
attracting attention here.
That was evident at a Sept. 11 meeting of the City Council’s Transportation Committee, where Carol Hunter, a senior planner with the WSDOT Urban Corridors Office, and Torsten Lienau, of CH2MHill, briefed members and visitors on the state of the study.
Starting with concerns raised by the council in previous briefings, Hunter spoke about the prospects for more transit service in the corridor. She said the study would incorporate data from a traffic-modeling program used by the Puget Sound Regional Council, from which a marketing plan will be derived to spur transit ridership.
Hunter also said her agency is in favor of extending the service area of Sound Transit east to include Snoqualmie and North Bend, but will not advocate for it.
“That might be something the elected in Issaquah might want to do,” she said.
The study assumes major improvements will be made to the Interstate 90 interchange at state Route 18, where a casino is to be built and where traffic is increasing rapidly.
Another element that is sure to come is “active traffic management,” or “speed harmonization.” Used successfully in Europe, the strategy employs variable speed limits in congested areas to reduce the incidence of collisions.
Hunter said one prime candidate for such management is the westbound approach to Issaquah, where vehicles in a downhill 70-mph zone can suddenly encounter traffic jams. To prevent this, electronic signs placed farther east could show a lower speed limit and a warning.
Long-term planning projections (to 2030) include major revisions to I-90 interchanges in Issaquah. These include a new overpass and HOV-only entry and exit ramps, to be placed somewhere between state Route 900 and Front Street North, and a completely revised Front Street interchange.
“Traffic growth in Issaquah is the highest in the entire corridor,” Lienau said.
When committee members asked about funding for all of the big projects, Hunter said there is none. But having the finished study in hand will be a valuable tool when lobbying the state Legislature.
The study should be completed early in 2009, with a final report expected in the spring. Further information is available on the WDOT Web site — www.wsdot.wa.gov. Click on “projects,” then “planning studies,” then the I-90 entry in the table.
Reach Reporter Jon Savelle at 392-6434, ext. 234, or firstname.lastname@example.org.