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In-Service Safety Series
In-Service Safety Series
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III. Overview of Slippery Roads

  1. Now we are going to talk about the first set of conditions: slippery roads
  2. What can make a road slippery?
    • Mud
    • Rain
    • Snow
    • Ice
    • Wet leaves
    • Hailstones
    • Sleet
    • Sand or gravel
  3. Before we talk about each of these weather situations, let's review some general driving conditions that are affected in slippery weather
    1. Road conditions
    2. Grade
  4. First, let's talk about road conditions
    1. The type of road surface affects the impact of the weather
      1. Asphalt is more slippery than concrete when it first rains because it contains petroleum
      2. Concrete tends to be less slippery than asphalt in rain and light snow
      3. Ice forms more slowly on a gravel road than on asphalt or concrete
      4. Gravel and dirt roads can change to mud after rain or snow melt
      5. Watch a sandy road after winter; the sand retains and freezes water; when it thaws, the wet sand is difficult to drive in
      6. Dry sand on roads reduces traction and can cause the school bus to slide or skid
      7. If it has been raining, mud from a construction site can be tracked on to an asphalt or concrete road immediately adjacent
    2. In addition to the road surface, you need to watch the road contours while driving in slippery conditions
      1. A high crown or crest
      2. The banking on the road
      3. Curves in the road
      4. Soft shoulders or road edges
      5. Potholes or frost heaves
  5. Next, let's talk about grade
    1. The grade (steepness) of the road makes every slippery situation worse
    2. This is true whether you are coming up a hill or down a hill
    3. Going up a steep grade in slippery weather
      1. You want to be able to climb the entire grade in the same gear
        1. Having to downshift will cause you to lose traction
        2. So you need to use a low gear
      2. Downshift before you get to the grade
      3. Keep moving at a slow and steady pace
        1. Maintain your momentum
      4. Make sure you have adequate snow tires and/or chains
    4. Going down a grade in slippery weather
      1. Slow down as you approach the grade
      2. Before you start down the grade, gear down
      3. Brake carefully, using the appropriate method for the kind of brakes you have
  6. Are there any questions about road conditions or grade?
  7. In addition to driving conditions being affected by slippery weather, how you drive is also affected
    1. How to handle a skid
      1. Slick surfaces exaggerate any movement
      2. If you brake too hard or turn too hard or drive too fast, you can go into a skid
      3. What do you do if you start to skid?
        1. Ease your foot off the accelerator
        2. With non-ABS brakes lightly tap the brakes to gradually slow down the school bus. With ABS brakes do not pump the brakes, apply steady and continuous pressure
        3. Take your foot off the brake and begin turning in the direction of the skid
        4. If you turn too far, the school bus may skid in the opposite direction
        5. Turn gently the other way, again in the direction of the skid
      4. Are there any questions on how to handle a skid?
    2. Avoid getting stuck or spinning your wheels
      1. Keep the bus moving slowly and steadily forward in gear
      2. If the wheels start to spin, let up slightly on the accelerator to let the wheels take hold
      3. If the school bus stops moving, don't continue spinning the wheels
        1. Further spinning will only dig the wheels deeper
      4. Point the wheels straight and “rock” the school bus by alternately putting it in reverse and then in low
        1. This will usually pull the school bus out of the stuck place
      5. If rocking doesn't work, push some material around the rear wheels to provide friction
        1. Kitty litter
        2. Crushed rock
        3. Tree branches
        4. Pieces of timber
        5. Burlap
  8. Are there any questions about driving in slippery conditions?

III.C - Distribute Handout #2, Slippery Roads Overview


III. Remind participants that their first preference should always be to avoid an adverse weather situation. This module deals with what to do if you haven't been able to avoid it. You will discuss those situations where the school bus driver has to decide what to do.

III.C. Distribute Handout #2, Slippery Roads Overview. Review it with the participants.

III.D.1.a. This is especially true if it hasn't rained for a while.

III.D.2.e. Frost heaves are an upthrust of ground or pavement (they are also called frost bumps) that occur when moist soil freezes. They are most apt to be seen in early spring as the ground thaws and then refreezes.

III.E.4.b. In extremely slick conditions, don't choose too low a gear. The engine compression can prevent the rear wheels from turning fast enough to maintain traction and the school bus may skid. Choose a higher gear and lightly apply the brakes.

III.E.4.c. See Section II, Good Things to Know, Part D, on slowing the school bus.

III.G.1.b. When a vehicle is skidding, the locked wheels lead. This means that, if the rear wheels lock and the vehicle is heading in a forward direction, the back of the vehicle is going to swing around and lead.

III.G.2.e. Watch that no one is behind the school bus when material has been placed under the wheels. The material can be thrown as the school bus gets free.

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