City of Sammamish - COVID-19 (Coronavirus) Information & Resources
City of Sammamish’s overlay program provides major street maintenance of roadways. This maintenance include street overlays, pavement rehabilitation, curb and sidewalk repair and appropriate Americans with Disabilities (ADA) retrofit work. Pavement overlay projects also replace pavement markings and vehicle detection loops for traffic signals. For its annual overlay program, the City allocates a certain amount of dollars each year to pave roadways. In 2020 the City allocated $3,500,000.00.
Over the past 10 years the City has overlaid approximately 75 miles of our roadway.2009 to 2018 Pavement Overlay History
current program projects
2020 Curb Ramp Retrofit
2020 Pavement Overlay
What is an overlay?
Overlay is the paving of a second layer of asphalt over existing asphalt with a mixture of coarse rock and asphalt, about two inches in depth. This process extends the useful life of well-traveled streets by up to 20 years.
Depending on the degree of cracking, crumbling or sinking, some areas on the roadway may be cut out and patched before the overlay. The overlay process reduce pavement distress, lower noise levels, reduce life-cycle costs, and provides long-lasting service.
Besides overlaying the streets during the annual overlay project, contractor’s crews also repair broken curbs, sidewalks, and rebuild the sidewalk ramps to meet the most current ADA (Americans with Disabilities Act) guidelines.
ADA sidewalk ramps makes sidewalks easily accessible to all users. After the curb and sidewalk repairs are completed, crews prepare the roadway for the asphalt overlay.
Defects or cracking in the asphalt may be removed and patched. Crews then mill and grind the roadway to allow for the placement of the new asphalt surface to match the existing gutters and cul-de-sac/median islands.
During resurfacing, dump trucks bring hot asphalt to the project site. A paving machine lays down hot asphalt, and large rollers compact the asphalt as it cools. Manhole covers and other utility covers in the roadway are raised to the top of the new asphalt and adjusted to the new roadway elevation.
When the street reaches its optimum compaction value based on WSDOT standards and has cooled enough to safely carry traffic, crews reopen travel lanes. At signalized intersections, crews place new loop detectors into the pavement. Finally, crews add new lane markers, crosswalk stripes and arrows.
For further in-depth information, see our PowerPoint from the March 13, 2018 Study Session.Study Session PowerPoint
If you have any questions about the construction please call or email Ben Ressler.
Street Cuts - Ordinance # 02001-78 prohibits the excavation of resurfaced or newly constructed roads for a minimum of five years following construction or paving. If you are planning to have any underground utility work done, such as water, sewer, telephone, gas, electrical, etc., you are strongly encouraged to expedite this work if it involves utility work under the new pavement. Please call us as soon as possible to coordinate this work.
2019 No-Cut Streets MapThis map is intended to be used as a reference and is not meant to be used for official purposes. Always check with the City to know if a road is considered a "No-Cut".
Updated: BR 12.15.20