Snow Storm & Plow Information

Residential Streets and Plowing Shifts 

Residential Streets - After residential streets are plowed, residents will not necessarily see bare pavement. The emphasis for residential streets is to create a single passable lane down the middle that can be navigated by passenger vehicles equipped for winter travel. 

Blocked Driveways - During heavy snowfalls, problems arise for residents when mounds of snow left on the sides of streets may block driveways. Although a concerted effort is made to avoid this, it is not always possible. Residential streets are plowed down the center of the street in an effort to avoid covering sidewalks, parked cars, and blocking driveways. The City of Thornton does not remove or haul away snow as part of this program.


​​The city divides storms into three classes and responds accordingly. In the event of any snowstorm, the city's first commitment is to clear the primary routes, then secondary routes — and keep them cleared. In the case of a Class III storm (and only in this case) the city will also bring on contract equipment to clear all 738 lane miles of residential streets.

  • Class I - A storm that lasts less than 12 hours; snow accumulations of less than 4 inches.

  • Class II - A storm that lasts more than 12 hours; snow accumulations between 4 and 8 inches.

  • Class III - A storm that lasts more than 24 hours, snow accumulations greater than 9 inches. 

Cleared Primary Routes and Residential Streets Map

Definitions ​​for the purposes of the Snow Plowing Status map...

  • ​​A primary route is considered In Progress when a plow has begun a first pass on it.
  • A primary route is considered Plowed when it is clear of snow from curb to curb.
  • Residential streets get one pass down the middle of the street. They are considered Not Plowed before the pass has been made, and Plowed after the equipment has passed through. There is no In Progress status for residential streets.