Preserving Bothell's pavement

Program Update

Learn more about what we've accomplished with Safe Streets & Sidewalks funding since the levy started in 2017 by checking out the Safe Streets & Sidewalks Comprehensive Report.

Annual Arterial Overlay Program

Asphalt pavement deteriorates over time:

Tiny cracks appear on the surface.
Light rutting appears in the wheel paths and cracks grow larger.
The roadway doesn’t drive as well.
Rainwater doesn’t shed as freely.
Water seeps into cracks and erodes the gravel supporting the asphalt.
Potholes appear, and driving is rough.

At this stage, only extensive and expensive repaving can repair the roadway. The annual budget varies depending on grants awarded. The target annual investment for this program is $3 million.

Where does the money come from?

Revenue Source	2024 Revenue
Safe Streets & Sidewalks Levy	$2,071,802
Grant Funds	$7,550,736
Taxes and Fees (real estate excise tax, solid waste, and street preservation fees)	$93,035
Total	$9,715,573

What does this work include?

Bothell conducts field surveys every year. Typically, half of the City is evaluated each year. We measure the size and type of cracking, the surface condition (weathering and raveling), ruts, and patching. Based on the survey data, the roadways are assigned a Pavement Condition Index (PCI). This information drives the annual projects.

Preventive treatments are substantially less expensive than repaving, so more roads can be treated each year for the same cost. Preventive treatments, applied at the right time, extend pavement life by preventing rainwater from seeping into and undermining the pavement. This work is done in partnership with in-house asphalt patching projects.

Pavement Condition Index (PCI) Ratings

PCI	PAVEMENT CONDITION	PERCENT OF BOTHELL STREETS
85 - 100	Excellent	61%
70 - 85	Very Good	61%
55 - 70	Good	29%
40 - 55	Fair	10%
25 - 40	Poor
10 - 25	Very Poor
0 - 10	Failed	0%

Each street’s PCI rating is entered into asset management software that predicts the roadway’s future condition, based on historical PCI data, pavement preservation techniques, and spending levels. Based on the PCI, roadway classification, budget, and other factors, staff determines which streets will be paved each year.

Pavement preservation techniques: Added pavement life expectancy by roadway condition

Treatment	Comparative Cost	Very Good	Good	Poor
Slurry Seal	Low	7 - 10 years	3 - 5 years	1 - 3 years
Chip Seal	Low	7 - 10 years	3 - 5 years	1 - 3 years
Microsurfacing	Moderate	8 - 12 years	5 - 7 years	2 - 4 years
Overlay	High	10 - 12 years	5 - 7 years	2 - 40 years
Reconstruction	Highest	15 - 20 years	15 - 20 years	15 - 20 years