When there is a chance of snow and ice, the City prepares to enact its Snow and Ice Plan. The goals of the plan are to reduce life threatening and injury producing conditions and reduce interruption to commerce and damage to property. The Plan is also committed to limiting the environmental impacts associated with removing snow and ice.
When there is snow, sleet, ice, or other winter weather event, the City of Portland's top priority is safety. Transportation crews will do their best to minimize the inconvenience to residents and businesses and, if necessary, work around the clock.
Read a two-page backgrounder about the Snow and Ice Plan
The Portland Plow Map shows the City's snow and ice routes and Traction Advisory Areas. The City has approximately 4,700 miles of streets, of which 1,300 miles are arterials, and of those, approximately 518 miles are bus snow routes. In all, the City's network includes plowing and sanding 1,700 miles of lanes on those 518 miles of streets (which represents the distance traveled from Seattle to San Diego).
Because winter storms are so rare in our area, the City has a limited fleet of vehicles for performing these services. They are focused on the higher priority facilities and generally follow TriMet's bus snow routes. The Snow and Ice Plan establishes four service priorities:
A. Pre-identified hazard areas and critical locations (mostly bridges, overpasses, and critical intersections);
B. Arterials and major transit routes considered to be a minimum network that must be kept open to provide a transportation system connecting hospitals, Police and Fire stations, rescue unit locations, schools, if open, and major park-and-ride transit lots;
C. Additional arterials with a high daily traffic count, and major collector streets completing a network that connects major residential areas and local commercial districts; and
D. Neighborhood residential streets providing access to residential homes and businesses, and Central Business District crosswalks, bridge walks, stairways, and other selected locations.
Neighborhood residential streets are not plowed and sanded during snow and ice events, and crews cannot safely get plow trucks up and down many steep and narrow side streets in the hills. The City does not have the equipment and personnel to provide anti-icing, de-icing, sanding, plowing, and snow removal services on neighborhood streets.
Under all circumstances, major routes are routinely patrolled during adverse weather and treated as necessary to keep them open.
Snow removal on sidewalks and driveways is the responsibility of the property owner.
Traction advisory areas
Traction Advisory Areas are particular locations like steep hills, bridges, and critical locations on both the west and east sides of the city that are exposed to the elements and tend to freeze first. They're slick spots in winter weather.
Because of their hazardous and changing conditions in winter weather, the Traction Advisory Areas warrant extra caution and chains or studded tires if you choose to drive on these streets, hills, and bridges.
Maintenance Operations has authority to close streets or require traction devices. During major events, traction devices are usually required for West Burnside Street and Sam Jackson Road. Other known hazard areas and critical locations during the winter include:
- Bridges and overpasses that are exposed and tend to freeze first
- West Hills - NW Cornell Road, West Burnside Street, Sam Jackson Road, NW Skyline Boulevard, Germantown Road, SW Hamilton Street, SW Bancroft Street
- East Side - Mt. Scott, Mt. Tabor, Rocky Butte, SE Flavel, Marine Drive
- Council Crest is the highest point in the metro area at 1,073 feet above sea level
- Mt. Scott is 1,050 feet above sea level
- Mt. Tabor is 641.30 feet above sea level
- Powell Butte is 620 feet above sea level
- Rocky Butte is 609.30 feet above sea level
- Kelly Butte is 590 feet above sea level
Staffing and equipment
During a major snow and ice event, Maintenance Operations crews switch to 12-hour shifts to ensure 24-hour coverage. Truck drivers, large equipment operators, and other personnel staff equipment and maintain the stockpiles in the yards.
A total of 55 large dump trucks are fitted with snowplows and sand spreaders to clear streets, bridges, and overpasses of snow and ice. These trucks are used every day for filling potholes, flushing streets, and carrying materials to and from work sites for paving. The full fleet includes an additional 5 anti-icing trucks, 10 service trucks, 5 big-wheel loaders, 2 backhoes, 2 road graders, 2 emergency trucks, 2 street closure trucks, and 1 fuel truck.
Winter road conditions are affected by a number of weather factors. Crews monitor temperatures of the air, road surfaces, and the ground, wind data, relative humidity, dew point, visibility, and precipitation. Crews also monitor specific roadway conditions all around the city.
Road treatments include application of anti-icing and de-icing chemical, sanding, plowing, limited snow removal, and street closures. Rock salt is not used because of environmental concerns. It is corrosive to our bridges and harmful to fish and wildlife in our rivers and streams.
The City owns five trucks for anti-icing and de-icing streets, bridges, and overpasses. The chemical used is calcium magnesium acetate (CMA), the most environmentally-friendly effective treatment there is. Magnesium chloride is used in temperatures below 17 degrees to increase the effectiveness of the de-icing chemical and to prevent sand from freezing in trucks.
Anti-icing is normally carried out after the evening peak traffic period or before the morning rush because frost does not usually affect the road surface until late evenings or early mornings.
Read a two-page backgrounder on why the City doesn't use salt.
Arterial streets are plowed first during a storm. Those are the major streets leading toward downtown Portland in the early morning and away from downtown in the afternoon. Non-arterial streets are plowed only when the arterial streets are cleared. Plan your route accordingly.
A sanding truck with a plow is typically allocated to the West Hills and another to the East side, to be used as necessary.
Crews use snowplows when snow begins to accumulate at a depth of one inch or more on the street surface.
Streets of grades over 14% are not able to be treated because such an operation would endanger crews and equipment.
After each storm, the streets on the snow and ice routes are mechanically swept. Portland performs street sweeping as soon as possible after the end of a storm event to try to minimize the amount of sand entering the drainage system. Portland typically recovers and recycles 60-75% of the total sand that is applied to streets in a snow and ice event.
Sidewalks, driveways, and overhead hazards
Property owners are responsible for their sidewalks and driveways, including the removal of snow, ice, slippery leaves, and other debris. By City Code, property owners are liable for personal injury and property damage caused by snow, ice, and other debris on sidewalks.
As soon as possible, clear your sidewalks and driveways across pedestrian paths of snow and ice, leaves, and debris after a snow event. Maintain at least a three-foot-wide path so pedestrians and transit users have a safe place to walk. Property owners are also responsible for advising pedestrians of any danger of falling snow or ice from their buildings. Please make arrangements to post an advisory (sign or sandwich board) and eliminate the hazard.
As the snow plowing operation proceeds, a snow berm develops. It is impossible to plow without leaving a berm. Individual property owners are responsible for clearing away the snow berm from driveways and entrances. Pile shoveled snow where it can be absorbed into the ground, not on the street and public right-of-way.
Businesses hiring contractors to remove snow from lots should store the snow on your property, not dump it on the street and public right-of-way.