Street Maintenance Programs
Chip Seal - Test Project Late August 2007
In late August the City will test a street maintenance process called “chip seal” on Harbour Heights Parkway. This process of maintaining pavement is being evaluated in an effort to assure that we will continue to enjoy the generally good quality streets we presently have.
Mukilteo presently uses a Pavement Management System for guiding street maintenance decisions throughout the City and is in the process of updating that information. Mukilteo is fortunate in that most of it streets are still in reasonably good condition. What this means is that preventive maintenance alternatives can be used before we need to use an expensive “grind and overlay” process where the worn out pavement is ground off and a new 2-4 inch layer of asphalt is applied. Simple preventative maintenance approaches can keep a street in good condition for years beyond their normal life at less cost. Most Cities are discovering they do not have the funds to grind and overlay the streets, so they are looking for ways to extend the life of the street before repaving is needed.
One of the most effective pavement maintenance process used today is chip seals (see Chip Seal Program Presentation to City Council - July 16, 2007). It is actually a normal step in the pavement life-cycle maintenance process that sometimes gets skipped. To determine whether the process will work well for Mukilteo, we will be installing a test project using this technology. For this project we have selected all of Harbour Heights Parkway from Harbour Pointe Boulevard to the west end cul-de-sac. This project is presently scheduled for late August. Wet weather can delay the project.
The alternative to doing preventive seal coats (a chip seal in this case) is to let the existing pavement slowly, over a 15-17 year period (on average), deteriorate until it is replaced (ground off and repaved). Sometime around the 7-10 year period is when a seal coat should be applied. If that is not done, crack sealing should be done and generally will have to be done several times until the pavement is ground off and replaced. Of course, by the time the pavement is replaced around 15-17years, the condition of the pavement is generally quite poor – providing both a poor ride and unfavorable aesthetics.
For additional information regarding this project contact Public Works Director Larry Waters at 425.355.4141, Ext. 225.