Why do state-owned roads and highways look better than city roads during winter severe weather events? During last month’s snow and ice weather event, we were asked this question over and over. The answer boils down to the environment and conditions of our roads, which drives the type of equipment and techniques used in the city limits:
- A steel-bladed snowplow is the most commonly used type of equipment and is ideal for removing packed snow on roads. The City of Longview uses snowplows with rubber-blades because we have concrete streets, many with uneven panels. The city streets also have manholes, pavement markings, catch basins and water valves that can get caught and damaged with steel-blades. Rubber-blades preserve these assets and prevent costly repairs to our infrastructure due to damage from steel-bladed plows.
- When the snow begins to accumulate along with extremely low temperatures, rubber-blades are not as effective as using sand and gravel as a traction additive.
- The City of Longview utilizes three snowplows with prioritized routes. Two of the snowplows have sanders and the third snowplow has a deicer sprayer. We also have the wheel loader and grade tractor, which work great in parking lots.
- The equipment we have is adequate to address winter weather events and is similar to other municipalities our size within the region.
- The City uses and makes its own salt brine, which is a solution applied to roads before and during cold weather events. We use this salt brine for several reasons.
- The cost of salt brine is about $.20 per gallon, and we can make as much as we want on demand. The alternative solution is magnesium chloride, which costs about $1.50 per gallon, and you must purchase and store as much as you think you need each season. While magnesium chloride works very well, it is not best suited for our budget.
- Our area receives a lot of precipitation. Magnesium chloride is better suited in colder, dryer climates because it will stick to roads better without the threat of washing off from rain. Most of our snow events begin with rain and then transition to snow. By the time it is cold enough to make a difference, whatever treatment is applied has washed off, rendering the efforts useless.
- Storage and availability are major considerations. The City orders salt by the truckload each spring and typically utilizes 24 tons of rock salt per year, or approximately 20,000 gallons of brine material. Alternatively, if the City used magnesium chloride, it would need to purchase a large tank, have it filled several times per year, and risk timely delivery as suppliers become too busy to deliver the material during snow events.
Challenges in Removing Packed Snow and Ice
- Packed snow and ice are often tightly compressed and bonded to the road surface. This compaction makes it difficult to break the bond and remove the frozen precipitation effectively.
- In extremely cold conditions, snow and ice can become harder and more resistant to traditional snow removal methods. Salt, for example, may be less effective at melting ice when temperatures are very low.
- The repeated cycles of freezing and thawing can lead to the formation of hard-packed layers of ice. This process creates a challenging surface to remove as the ice may have multiple layers with different degrees of hardness.
- Roads that receive limited sunlight may have slower rates of natural melting. Sunlight can help melt snow and ice, but shaded areas or those with limited exposure to sunlight may retain frozen precipitation for longer periods.
- Vehicles frequently driving over snow and ice can further compact it, creating a dense layer that is harder to remove. Traffic pressure contributes to the formation of icy patches and makes the removal process more challenging.
- Snow removal equipment, such as snowplows and blowers, may have limitations in dealing with densely packed snow and ice. Some equipment may struggle to break through hardened layers, especially if they are not designed for extreme conditions.
- During severe winter weather events, there may be limitations on the availability of resources such as salt, sand, or deicing chemicals. Longview prioritizes arterial streets and heavily used roads, leaving secondary roads with packed snow and ice for longer durations.
- Using certain aggressive methods to remove packed snow and ice, such as heavy machinery or chemicals, may pose safety concerns. Public Works crews need to balance effective snow removal with the safety of both operators and the public.
While jurisdictions have more equipment and/or manage their roads differently, it’s important to understand the unique and varying factors that contribute to the decisions such as road surface type, weather conditions, and climate.