Street, Pedestrian & Bicycle Facilities
|Repaving and new walkway on 86th Ave|
Arterial Street Programs
The arterial street improvement program provides for the resurfacing and upgrade of Mercer Island's 26 miles of Arterial Streets on an approximate 25 year cycle. In general, one arterial street improvement is constructed each year. Typically, major pedestrian and bicycle facility improvements are constructed in conjunction with arterial improvements.
Annual Street Maintenance (Residential Street Improvements)
The City's Street Maintenance Program provides for the resurfacing and upgrade of approximately 52 miles of residential streets on a 35 year cycle. It is difficult to plan residential overlay projects too many years in advance due to their ever changing conditions, impacts from large-scale home construction, and the effects of ongoing water and sewer system improvements on street conditions.
How Are Street Projects Prioritized?
The City's Street Engineer performs a street pavement condition survey every three years using an outside contractor with custom-equipped vehicles. This survey serves as a tool to rank all City-owned and maintained streets based on their current condition. The Island's streets wear at different rates based on a variety of factors. Currently, the Arterial Street Network is on an approximate 25 year life cycle for resurfacing or reconstruction and the residential streets are on a 35 year cycle. The results of the survey help determine the priority of future street improvements. The survey uses five criteria to determine the pavement condition rating.
Visible Pavement Distress
Cracks, potholes, settlement, and pavement patches.
Ability of the soil or gravel underneath the pavement to support the pavement and traffic load.
Condition of the pavement surface.
Poor drainage can result in premature base and surface failures, resulting in reduced pavement life.
Streets with high traffic volumes will have surfaces that wear more rapidly and will accelerate the growth of pavement distress.
Other factors, such as utility improvement schedules, the need for drainage improvements, sequencing with other street work, and long range planning are then considered before developing a final street improvement program. Residential street overlays are also linked, where feasible, to arterial street projects to create an economy of scale by performing more road improvements under one large contract.
What Streets Will Be Improved In The Future?
The 6-Year Transportation Improvement Program map shows the locations of arterial and residential streets currently planned for improvement. The plan may change as a result of future street condition surveys or a shift in other priorities. Past street improvement areas can be viewed on the History of Street Resurfacing map. The City Council approves the prioritization of arterial and residential street improvement projects every spring as part of the adoption of the City's Six Year Transportation Improvement Program.
Pedestrian and Bicycle Facilities
The City continues to develop a comprehensive system of pedestrian and bicycle facilities as part of the Transportation Element of the Comprehensive Plan. Projects are directed at improving conformity to standards, connectivity, and signage for non-motorized facilities throughout the Island.
|Pedestrian & Bicycle Path along the I-90 Corridor|
The Pedestrian and Bicycle Facilities Plan, originally approved in 1996 and updated in 2010, guides investments and other actions relating to Mercer Islandís pedestrian and bicycle facilities such as trails, crosswalks, bike lanes, and sidewalks. The plan includes a complete list of projects and improvements to be constructed as budget allows, based on Council prioritization and approval.
The majority of target projects are generally identified in the current Pedestrian and Bicycle Facilities Plan, however, some new projects can be added as part of the annual Transportation Improvement Program (TIP) update and approval process.