Snow and ice control program in Kansas City

Jere Meredith
Assistant Engineering Director
City of Kansas City, Missouri

Kansas City, Missouri, covers an area of 318 square miles containing some 2,300 miles of roads. Snow and ice operations are directed by the Street and Traffic Division of Public Works with substantial support from the Parks and Recreation and Water Services departments. Declaration of a snow event is initiated by the command post which performs the following tasks:

  • Monitors the status of all salt/plow operations.
  • Maintains a log of all service calls and response activities.
  • Monitors weather conditions, forecasts, and disseminates to the field.
  • Analyzes reports from the field and changes future operations where required.
  • Forwards emergency calls from the Police and Fire departments to district offices.
  • Handles citizen requests and complaints.

Snow, ice, and freezing rain can occur anytime in Kansas City during the fall, winter, and spring months. Normally, winter storms can be expected from November to April. The city receives about 20 inches of snow and several ice storms annually and budgets $2,000,000 for response.

Snow route designations

The roadway network in Kansas City comprises 890 miles of arterial streets that must be salted/plowed during snow or ice storms. These streets are divided into 27 “A” (major arterials), 27 “B” (secondary arterials), and 8 Parks routes. The three maintenance districts of the Street and Traffic Division salt 54 routes (765 miles) and plow 14 routes (191 miles). The Parks and Recreation Department plows 8 routes (125 miles), the Water Services Department plows 9 routes (146 miles), and private contractors plow 27 routes (428 miles).

In addition to the above, certain local streets have a history of being problematic whenever there is freezing precipitation. Each maintenance district has established routes (total of 40) that include historically known slick streets within its area. These are defined as “C” routes and are salted/plowed by the division.

Approximately 1400 miles of residential roadways, designated as “D” routes, are plowed by private contractors. Contractors are summoned when approximately two inches of snow have fallen and the forecast calls for further accumulation.

“A” and “B” routes are the first to be salted/plowed during snow removal operations and service is continued until full width bare pavement is achieved. After completion of the “A” and “B” routes, the “C” routes are treated as needed. Simultaneous with the “A” and “B” routes, a 12-foot wide driving lane is plowed down the center of “D” routes.

Decision-making information

Several factors such as air temperature, pavement temperature, pavement conditions, precipitation, dew point, wind speed and direction are used in execution of the snow and ice control program. Generally, salt/plow operations begin when the forecast is for freezing temperatures with at least a 50 percent chance of precipitation. Information on the weather is obtained through several sources:

  • Local TV, radio, and National Weather Service
  • Weather Channel
  • Internet
  • Actual road conditions, hand-held sensors

The following high-technology methods are also used:

  • SCAN (Surface Condition Analyzer): The SCAN system provides an electronic means of monitoring real-time surface and atmospheric conditions. The system is used to produce a site-specific pavement weather forecast called a SCAN cast.
  • The system consists of groups of sensors to gather data, phone modems for communication, and computers to store and present data in a useful form. At present, there are 20 sites (small electronic weather stations) in the metropolitan area; seven belong to the city and the CPU is located at the command post. Seven agencies have agreed to share data.
  • DTN: A system that monitors and tracks storms nationwide. Through this system the path and timing of the storm is predicted.
  • Pager Delivered Forecast : This pilot program provides the latest weather information via pagers directly to city staff.

Commodities and storage facilities

The division orders and stores salt, calcium chloride, and sand for the winter maintenance program. Good storage facilities are vital. They must have sufficient capacity and good cover, preferably under roof, to prevent loss of material and to protect the environment.

Capacities of the city’s four salt domes are shown in the following table:

Location

Capacity in Tons

District 1

6,600

District 2

10,600

District 3

8,000

Shared MoDOT

8,000

In the fall of 1999, the city and MoDOT opened a combined service center that includes a salt storage facility of 8,000 tons. The agencies entered into an agreement to share the capacity of the dome and its maintenance costs.

Application and equipment

The application of salt alone or a mixture with liquid calcium chloride depends on the precipitation, temperature, and snowfall intensity. Applying salt early prevents snow and ice from bonding to the roadway surface. The salt application rate ranges from 200 to 800 pounds per two-lane mile, depending on the storm conditions.

The application of salt alone is recommended when there is enough frozen precipitation on the pavement and the temperature is above 25° F. However, if the temperature is 25° F and falling, salt loses its effectiveness. Under these conditions, a mixture of 8 gallons of liquid calcium chloride to 1 ton of salt is used. The calcium chloride is applied via an overhead spray bar or at the spinner through the use of saddle tanks. Eighty percent of the division’s spreaders are equipped with saddle tanks. During icing conditions, sand is often applied to pavement surfaces to provide increased traction for motorists.

Specialized equipment is required to execute the program. Equipment is used to spread salt or apply salt brine. Spreaders with saddle tanks apply liquid de-icers at the spinner instead of prewetting at the maintenance yard.

A self-standing spreader rack was invented in-house in an effort to improve equipment handling. It also improves employee safety and provides easier access for cleaning. The spreader stand requires fewer personnel to load or unload than conventional methods and can be operational in half the time. Because they can be loaded easier, units can be washed more frequently, resulting in better maintenance. Each spreader rack is independent of the spreader and with proper care can be reused when spreaders are changed out.

Wingplows were added to the tandem fleet in 1998. On some routes, they have eliminated either one truck in plowing operations or one pass because of the cut width. Usage of wingplows has proven beneficial on multiple lane arterials and rural routes with shoulders. On rural routes, the shoulders can be plowed in the same pass as the travel lane. This eliminates multi-passes and drifting problems have also been reduced.

During the 1998/1999 season, several routes, about 30 miles, were pretreated with salt brine in an attempt to prevent or delay a snow/ice bond from forming. When the pavement temperatures were 20° F or greater and snow or freezing rain predicted, applications of 30-gallons/lane mile of salt brine were made prior to the event. This usually occurred 12 to 24 hours in advance of the storm. The salt brine liquid was applied from truck-mounted spray tanks on pre-assigned roadways and bridges. The salt brine was made at one location and two trucks were used for the program.

Results from the winter experiment were positive and plans to have a salt brine facility at each district for the coming season have been prepared. Salt brine liquid will continue to be applied in advance of the storms to prevent snow/ice bonds from forming. The liquid application ability was expanded from two units to 15 for the winter of 1999/2000.

These policies, procedures, and guidelines, along with the storage facilities and equipment, have enabled the dedicated staff to carry out a successful winter maintenance program in Kansas City. This program has provided the citizens of Kansas City with a reasonably safe driving environment in inclement weather.

For more information, contact Jere Meredith at 816-513-2665 or jere_meredith@kcmo.org.