West Lake Sammamish lights | Some lanes widen, others close

Q: The stoplight for traffic heading east on Northeast 51st Street and turning left onto West Lake Sammamish Parkway stays green for only 10-second increments (including the time it is yellow). During rush hour in the afternoon, you often have to wait several light sequences to make this left turn, even if there isn't much traffic headed south on West Lake Sammamish. It seems to me that traffic flow would be better if the light were green for more time (say 20 seconds) and then red for a longer time, because people can't react immediately to a change in light and then may choose to stop as soon as they see yellow. Can you tell me why they leave the green-light cycle so short for this turn?

A: The signal timing at this intersection favors West Lake Sammamish Parkway because this particular section of it is considered a "principal arterial," while Northeast 51st Street is a "minor arterial," said Redmond project engineer Paul Cho.

At this intersection, the southbound right lane of West Lake Sammamish Parkway becomes a right-turn-only lane, which forces those in the lane who want to continue south to merge into other lanes. And that can be tricky because this right-hand lane queues up quickly.

Giving a greater percentage of the green light at this signal to West Lake Sammamish Parkway reduces accident potential by keeping southbound backups to a minimum, Cho said.

The city is working on a project that will connect this traffic signal to its new traffic-management center, now under construction. This will allow the city to more closely monitor the fluctuation in traffic patterns and be more sensitive to traffic demands, Cho said. The signal should be added to the center by the end of the year.

In the long term, the city soon will begin the next phase of the West Lake Sammamish Parkway improvement study, which may include additional southbound lanes that would alleviate queuing problems. If these lanes are added, the traffic signal may be adjusted to give more green-light time to Northeast 51st Street, Cho said.

Q: I live in Kenmore, near the Juanita area of Kirkland, and drive on Simonds Road Northeast every day. For the past many months, the right northbound lane has been closed, with barrels and cones and a large flashing sign saying "Merge Left." We have never seen anyone working on the road, and it just got repaved last year. What gives?

A: A section of the road slid during last winter's heavy rains. When that happened, King County Road Services closed one lane for safety, said Metro spokeswoman Linda Thielke.

The county placed monitors in the slope to detect ground movement, which continued after the slide. Since then, county crews have been drilling for soil samples, researching an engineering fix and watching the ground to see if movement has stopped, Thielke said.

Now that the ground is drying out, it seems more stable and the county can proceed with a fix. Most likely, a permanent drainage system is needed under the roadway, and once that is installed the road surface can be repaired, Thielke said. However, an exact construction schedule is unknown because permit and funding issues have not been resolved.

Update

The newly widened Highway 202 (Redmond Fall City Road) was completed Thursday. The widened portion between the Highway 520 interchange and East Lake Sammamish Parkway in Redmond will help alleviate previous congestion for motorists driving between downtown Redmond and the Sammamish Plateau. Nearly 27,000 cars and trucks drive through this area every day, said state Department of Transportation spokeswoman Melanie Coon.

This is only the first stage of an $84 million project to widen three miles of Highway 202. It began in late 2004 and included improving the intersection where the highway meets the parkway. Bicycle lanes, sidewalks, drainage, landscaped medians, signage upgrades and signal revisions were also added at the Highway 520 exit ramp and at Northeast 70th Street. A traffic camera has also been installed at the intersection of 202 and the parkway.

The second phase began in February and is expected to be completed in late 2009. It includes adding two new lanes from East Lake Sammamish Parkway to Sahalee Way, as well as retaining walls, noise walls, bicycle lanes and sidewalks, and replacing two bridges where Evans Creek flows under 202. Crews will raise the roadway 14 feet between 196th Avenue Northeast to 204th Avenue Northeast to accommodate an ancient landslide.

Early warning

Bellevue: Expect daytime closures of the eastbound I-90 car-pool lane between the I-405 interchange and 150th Avenue Southeast from 6 a.m. to 2 p.m. Monday through Friday. Closures of the westbound I-90 car-pool lane in the same stretch are planned from 10 a.m. to 3:30 p.m. Monday through Thursday.

• Expect nighttime closures of the eastbound I-90 onramp from 150th Avenue Southeast and the left lane on the eastbound I-90 exit to 150th Avenue Southeast from Monday through Thursday, 10 p.m. to 5 a.m. Signs marking detours will be in place.

Kirkland: Up to three I-405 northbound lanes near Northeast 128th Street will be closed every night except Friday. The first lane will close at 9 p.m., and up to three lanes will be closed by midnight. All lanes will reopen by 6 a.m. each morning. On Saturday night the first lane will close at 7 p.m. and all lanes will reopen by 11 a.m. Sunday.

• Weather permitting, all I-405 onramps at the Northeast 124th Street interchange will be closed from 9 p.m. to 5 a.m. Monday through Thursday for paving, striping and setting barriers and guardrails. The northbound offramps will remain open.

Very early warning

• All lanes in both directions of the Evergreen Point Floating Bridge will be closed from 11 p.m. June 16 to 5 a.m. June 19 for annual maintenance. The weekend closure will include all of Highway 520 between 92nd Avenue Northeast on the Eastside and Montlake Boulevard Northeast in Seattle. Drivers crossing Lake Washington will be detoured to I-90, I-405 or Highway 522.

• In Kirkland, expect closures of all southbound lanes at Northeast 124th Street each night from 11 p.m. to 5 a.m. from June 19 to 22 to set girders for the new Northeast 128th Street bridge at Totem Lake. The DOT has set June 23-27 as the new dates to close all lanes of northbound I-405 in Kirkland to lower the northbound lanes 3 feet to provide enough vertical clearance under the Northeast 124th bridge.

Lisa Chiu: 206-464-3347 or lchiu@seattletimes.com