Spot a pothole? Call 406-582-3208 and we'll smooth things over.
Departments > Public Works > Streets > Pothole Patching

Pothole Patching

Potholes are common to areas of the country that generally have several freezing-thawing conditions during the winter months. A pothole starts as a small failure in the road surface where water has seeped through cracks and into the road base. As the water freezes it expands; then when it thaws a void is left under the asphalt. As vehicles are driven over the voided area the asphalt fails causing a pothole to form. Street Crews try to prevent this from happening by crack sealing any cracks they can find during the spring, summer and fall months. Crack sealing is the process where the cracks in the street are sealed with hot rubberized material which prevents the water from seeping in.

A patched potholeIf a pothole does form, the crews will use two different types of material to fill the hole depending on the time of year. The preferred process for warm weather months is to use hot mix. Hot mix is asphalt that is heated to about 300 degrees which when cooled hardens to match the road. Potholes when patched with Hot Mix will look like the repair that was completed at the corner of 8th Ave. and Story St.  Unfortunately the asphalt companies do not start making hot mix until the end of April or early May so during the winter months the crews use Cold Mix. Cold Mix is asphalt that is warmed before being put in the hole, because it is not heated to the required temperature it will not harden to the extent of Hot Mix.

When there are several potholes forming close together on one stretch of the street the crews will use a process called Blade Patching which is when the crew will put a layer of hot emollient on the street and then pour Hot Mix over that, which seals and smooths the road. The crews had used this process to repair Babcock St. between Rouse Ave. and Wallace Ave. They mill out a small section of the street next to the curb so when they put the hot mix over the emollient the street will be level with the curb. It is an interesting process.

There are not enough City Street Crews available to traverse every street within the city on a regular basis so we depend heavily on the public to let us know when pothole repairs are needed. We have a dedicated phone line specifically set up for residents to leave a message to report a pothole, that number is 582-3208. Crews try to make the repairs within one week of receiving the report. As always if you have any questions or concerns feel free to contact the City Shops Complex at 582-3200. 

Re-paving a street
A pothole patch with cones