A major component of the City’s 20-Year Arterial Street Plan includes maintenance work designed to keep the “good streets good” and to improve streets with poor pavement that will need more work later. The City’s Street Department completes a variety of maintenance work every year in arterials in and residential streets. Often, maintenance work also is contracted and out and completed by contractors.
Here’s a look at grind & overlay work planned on arterials in 2021 by the City’s Street Department and estimated start dates for the work:
The Department is working to plan out up to six years of arterial maintenance work to provide more predictability for citizens. View the current version of that plan.
2612 filled as of 07/29/2021
While grind and overlay work provides better outcomes for our citizens, the need for pothole repairs continues. If you see a pothole, report it to the City’s Pothole Hotline at 311. If you are calling from outside the City limits, call 509.755.CITY. Street Maintenance Crews also are proactive in looking for potholes and getting them repaired.
The Street Maintenance Division repairs thousands of potholes every year in Spokane. Potholes are common to cities that experience winter weather patterns that consist of many freeze-thaw cycles. Potholes are formed when moisture seeps into cracks in the surface of a road and freezes, causing the water to expand. When the ice thaws that space is left empty and combined with frequent or heavy traffic over the crack, causes the asphalt to break and fail. Check out this site for more information on Pothole Formation.
The Street Maintenance Division installs between 150,000 and 250,000 linear feet of crack sealant each year. Sealing cracks prevents moisture intrusion into the pavement, helping to prevent potholes from forming. Crack sealant is a hot tar material that forms to the crack and seals it off.
The Street Maintenance Division installs about 4 lane miles of skin patching a year. Skin Patching adds 1-2 inches of asphalt on top of existing pavement. Skin Patching is a temporary way to improve the surface of an extremely deteriorated street when there is not funding for a complete repair. Skin Patching will last about 2 to 3 years before the cracks in the original pavement propagate back to the surface.
The Street Maintenance Division performs about 10 lane miles a year of grind and overlay. This process involves milling out 2-4 inches of asphalt to remove the failed pavement section and installing a new pavement section. This is typically only appropriate when the sub-base is structurally sound. This creates a pavement section that will last 7 to 10 years depending upon the volume of traffic. To improve the life of the overlay, crack sealant is applied along the joint between the old and the new pavement.
Spokane has approximately 2098 lane miles of paved streets. Arterial streets account for approximately 760 of the total lane miles. The Street Department manages its pavements by regularly assessing their condition and performing routine maintenance as far as budget constraints will allow. On average, Spokane's streets are in good condition, but many street surfaces are at or beyond their expected performance life.
City streets are visually inspected to document their existing condition. After roads are inspected, a condition index is calculated from 0-100. Generally, streets rated 70-100 are considered “Good.” One of our goals is to keep “good” streets in “good” condition. When roads begin to fail, they fail quickly and the costs to repair them increases dramatically. While it might be tempting to fix “failed” streets first, it would be so expensive no money would be left for preventive maintenance or rehabilitation of “fair” to “good” streets.
The City of Spokane uses a scoring system to indicate the conditions of street pavement. These categories include:
These condition ratings are used to establish priorities for street surface maintenance and rehabilitation. See more information on pavement ratings.