The city initiated its Chipseal Program in 1987. In the 19 years of its Street Maintenance Program, the city has sealed a majority of the eligible streets and has started the next phase of street preservation by returning to many of the streets sealed and protected early in the Program.
Missoula annually seals the surface of about 60-80 blocks of its streets using the chip seal method. The city will usually chipseal the last two weeks of every July. For more information, view the Chipseal Street List.
The main reasons for chipseasling Missoula's streets are:
Chipseal maintains the existing pavement in its present condition by delaying further aging due to sun exposure.
Chipseal changes the texture of the road for skid resistance.
Chipseal provides a moisture barrier.
Chipseal delays reconstruction and saves dollars and disruption for Missoula residents.
How We Chipseal
The first step in chipsealing is to clean the street of any debris and patch any holes or cracks.
The next step is to apply hot liquid asphalt on the street. The temperature of this oil is 140-180 degrees.
The third step is to apply the 3/8" washed aggregate (chips) as quickly as possible over the hot oil. Rubber-tire rollers are then used to set the rock into the fresh oil.
The last step of the chipseal process is to sweep the street to remove surplus chips.
What Residents Should Do
Please help this process by driving slowly and avoid spinning wheels on the newly sealed surface. Spinouts cause permanent ruts and may damage vehicle paint.
Trees must be pruned to a minimum of 14' over the street to the inside edge of the curb line (per Missoula Municipal Code 12.32). If your trees do not meet this requirement, they may be trimmed by the city in order to complete the Chipseal Program.