The Mercer Island Planning Commission continues its process to review and update the City of Mercer Island’s Comprehensive Plan Update. At tonight’s meeting at 7 p.m. at City Hall, the commissioners will consider changes to the present level of service (LOS) standard regarding traffic flow and congestion relief at key intersections.

By changing the level of service from C level to a D, the city can save money on the types of improvements needed to keep the service level at C. A excerpt from the Commission packet states the rationale behind the change:

Today, some of Mercer Island’s intersections are either worse than C, or soon will be with additional growth. The blanket standard of C is no longer realistic without creating unintended consequences and the need for significant investment in congestion relief. Staff recommends the change in LOS to provide a practical balance between reasonable short-term levels of traffic congestion and costly transportation improvements (eg. traffic signals, turn lanes, turn restrictions, roadway widening, concrete curbs, etc.) that may be out of scale with certain parts of Mercer Island. No change to the current LOS standard would require transportation improvements along several roadways and intersections. Staff raised the notion of lowering LOS with the City Council twice this year, both during a study session discussing transportation issues and during the annual adoption of the Six-Year Transportation Improvement Program last spring.

The City of Mercer Island establishes Level of Service (LOS) “C” defined as stable traffic flow with acceptable delays at intersections as the city’s established transportation level of service standard required under GMA.

Why not set a high LOS as a standard?

• More improvements may be required to meet the standard (more signals, wider roads, more traffic lanes, right of way acquisition).

• More improvements would require higher transportation funding/budgets resulting in less funding for repaving of existing streets.

• May relocate, burden or reduce growth in the Town Center.

• May encourage cut-through traffic from I-90

Staff recommends changing the level of service standard for arterial streets to LOS D. LOS D is defined as operating conditions with lower travel speeds and higher delays at intersections,  when compared to LOS C. Most cities have an adopted LOS standard of D, E, or F.”

The board packet also points out that many King County cities already have LOS D in place. They include Bremerton Issaquah, Tukwila and Burien.

For more, go to: www.mercergov.org/files/091714PCMtgPacket.pdf.