Snow Removal

Anti-Icing & Pre-Wetting: Enhancing Winter Road Safety

The City of Evanston utilizes anti-icing and pre-wetting strategies to improve road safety and reduce environmental impacts during winter weather events. These techniques help prevent ice from bonding to pavement, making snow removal more effective and reducing overall salt usage.

What is Anti-Icing?

Anti-icing is a proactive approach that applies liquid deicers to road surfaces before a snow and ice event. This treatment prevents snow and ice from bonding to pavement, much like using cooking oil to keep food from sticking to a pan. By disrupting the ice-road bond, anti-icing provides:

• More response time to snow and ice events

• Less salt usage during weather events

• Improved road conditions for drivers

What is Pre-Wetting?

Pre-wetting involves spraying granular salt with liquid de-icing chemicals before spreading it on the roadway. This process:

• Helps reduce bounce and scatter of the salt and keeps it in the driving lane

• Speeds up melting by providing the necessary moisture for salt to activate

• Enhances the effectiveness of de-icing efforts

Anti-Icing vs. De-Icing

Both anti-icing and de-icing help manage snow and ice buildup, but they differ in timing and efficiency:

• Anti-Icing (Before Snowfall): Prevents ice from bonding to pavement

• De-Icing (After Snowfall): Uses salt to break existing ice-road bonds

Since all solid deicers (such as salt) must be converted into a brine solution to work, applying liquid deicers beforehand makes the process more efficient and has a lesser environmental impact. 

Benefits of Anti-Icing & Pre-Wetting

• Environmental & Cost Benefits: Reduces salt use, minimizing environmental impact and operational costs.

• Faster Snow Removal Response: Helps crews respond more effectively, especially during rush hour snow events.

• Improved Cleanup: Reduces salt usage by up to four times compared to traditional methods.

• Cost Savings: Combined anti-icing and pre-wetting can cut costs by up to 30% compared to dry salt alone.

• Less Corrosion: Reduces salt scatter and minimizes damage to infrastructure and vehicles.

Evanston is a Salt Smart Community

As part of the City’s commitment to more sustainable practices, the City of Evanston participates in the Chicago Area Waterways Chloride Workgroup and is recognized as a Salt Smart Community. This recognition, developed by the Conservation Foundation, promotes best practices in winter road maintenance to enhance safety while reducing salt waste and protecting water quality. Evanston staff participate in annual chloride reporting and various trainings aimed at reducing the amount of chlorides that are released into our waterways.

Winter Snow & Ice Control

The Evanston Public Works Agency is responsible for keeping city streets and facilities clear and accessible during the winter season. Snow removal and ice control are provided for 190 lane miles of streets and 27 city-owned parking lots.

Snow & Ice Control Operations

Snow and ice control is considered emergency work, requiring response at any time of day or night. The City's approach to each storm depends on factors such as:

• Existing conditions and accumulation

• Snowfall rate and accumulation

• Moisture content and temperature

• Time of day and wind conditions

Materials Used

• Primary streets are treated with deicing rock salt during snowfall events.

• Secondary streets receive rock salt, but at a reduced application rate.

• Residential streets are salted as needed.

• After snowfall ends, deicers are applied mainly to intersections, hills, and curves.

• In some cases, rock salt is applied before a winter event to prevent icy conditions.

• Additives, such as brine, BeetHeet, or calcium chloride, are mixed into the salt to accelerate melting as needed.

Street Clearing Strategy

• Primary Streets: Crews aim to clear these to bare pavement during a storm.

• Secondary Streets: Plowed after primary streets are cleared, but may not be at bare pavement, depending on conditions.

• Residential Streets: Plowed after primary and secondary streets. These areas take significantly longer to clear than through streets.

• Public Parking Lots: Aisles are plowed as needed during storms to maintain access, with major clearing typically occurring overnight.

Snow Placement

• Snowplows push snow to the side, creating windrows along curbs and driveways. While inconvenient, this is the most efficient method for clearing streets.

• Do not shovel, blow, or plow snow into the street. Property owners must ensure that snow is not pushed across or deposited onto public roadways.

Sidewalk & Driveway Clearing

• Residents and property owners are responsible for clearing snow and ice from sidewalks with at least a 36” wide path.

• The City encourages property owners to keep sidewalks clear for pedestrians, especially children walking to school.

Refuse & Recycling Collection

• On collection days with snowfall, place carts away from the curb/road edge to prevent interference with plowing.

• Refuse and recycling carts should never be placed in the street.

• Snow and ice should be cleared away from carts to allow for servicing.

Parkway Repairs

Snowplowing may occasionally damage parkways. Repairs caused by City plowing will be made in the spring when materials are available.

To request parkway restoration, contact 311.

Snowplow Safety

• Do not follow snowplows too closely, as they make frequent stops and back up regularly.

• Never attempt to pass an active snowplow.