December 13, 1999
WOODINVILLE--During the Woodinville City Council Meeting of Dec. 6,Mike Bertram of the traffic engineering firm Entranco presented five traffic study alternatives designed to unclog the peak-hour bottleneck at the Hollywood intersection.
Each alternative would add a maximum of two lanes of several hundred feet in length to each intersection approach, which should move more cars through the intersection faster and reduce waiting time at the light, said Bertram. The optimum widening would feature two through lanes and two turn lanes from the north and south and two left-turn lanes from the west.
The new lanes would immediately improve the short-term traffic problem and fulfill the city's responsibility to provide long-term relief by accommodating future widening of SR-202 by King County, said Bertram. The new north and south lanes can only be extended a maximum of around 1,000 feet, because King County has jurisdiction over the road beyond that.
The length and number of lanes and whether or not to move Tributary 90 (Trib 90) were the main differences between the alternatives. The primary sticking points to the alternatives involves determining how much the road widening should impact which quadrants of the intersection, and their existing businesses.
Entranco's Ralph Nelson said not moving Trib 90 would be the least complicated alternative, because it would not involve the uncertain prospects of approval by those agencies, especially in light of the recent ESA protecting salmon. But not moving the stream would most limit construction options and require the city to acquire additional rights-of-way on the west side of 148th Ave. NE to accommodate the widening, he said. That would primarily impact the Chevron station and several residential properties in the northwest quadrant. Under the most beneficial road-widening alternative, the additional right-of-way purchases would remove the easternmost pump island of the Chevron station.
Every road-widening alternative would impact access to the mall in the Southwest quadrant, said Bertram. The addition of so many lanes would make access to and from the mall more difficult than it already is, possibly requiring its owners to relocate its east entrance further south and provide a north entrance/exit on NE 145th/SR-202, he said. The east side of the intersection allowed very little room to expand without severely impacting the elevation of parking lot entrances to the Woody's complex and the Hollywood School area, he said. That would be especially true if maintaining the existing location of Trib 90, the engineers agreed.
Nelson presented four options for changing the flow of Trib 90, all of which would allow widening the north leg of the intersection without buying more right-of-way in the northwest quadrant. He noted that the existing course of Trib 90 is little more than a steep ditch immediately adjacent to the road, not really fit for salmon habitat.
Alternative T5 would move the stream--which runs beside 148th NE on the northeast side of the intersection--several feet to the east. He said moving Trib 90 to the east "could allow us to create a real habitat, not just a ditch." The existing location does not allow planting habitat-supporting bushes and trees around the creek, Nelson said. Alternative T5 would also allow a more natural, wider and shallower stream course.
The four other stream relocation alternatives included two that would divert Trib 90 through pipes under the road to the west and southwest, while two others would intercept the stream above (east of) the Hollywood schoolhouse and divert it diagonally northwest to the existing pipe that carries it under 148th. Nelson said each of those options takes the 90-degree turn out of the existing stream course, which causes sediment collection at the angle that has resulted in continual overflow problems into the intersection during heavy rains.
Nelson said he favors one of the northwest diversions, because either would maintain the existing outflow. Diverting the stream due west or southwest would require extensive pipe laying and new outflows into the Sammamish River, both of which would cost over one million dollars. Alternative T5 would cost around $460,000. The northwest diversion costs are currently unknown, since some stream rights-of-way would have to be acquired from property owners north of the Hollywood School.