1. Highway Safety in Winter Weather
By Anthony Norman EIT

2. Winter Weather Facts Weather accounts for 23% of vehicle crashes
20% of Vehicle Crash Injuries
17% of Vehicle Crash Fatalities
Winter weather including snow, sleet, ice and slush, directly accounts for 10% of vehicle crashes.
Snow accounts for 4% of Vehicle Crashes
Sleet accounts for 3% of Vehicle Crashes
Ice accounts for 3% of Vehicle Crashes
The other 13% consists of wet pavement, rain, and fog.
Winter Weather usually occurs from December to March.

3. Winter Weather Snow, Sleet, and Ice Precipitation Wind
Pavement friction
Lane Obstruction
Visibility
Vehicle Maneuverability
Wind

4. Consequences of Winter Weather
Weather Conditions
Average Speed
Free-Flow Speed
Volume
Capacity
Accident Risk
Light Winter Weather
-3% to -13%
-2% to -13%
-5% to -10%
-4% to -11%
Increased
Heavy Winter Weather
-5% to -40%
-5% to -64%
-30% to -40%
-12% to -27%
Visibility
-10% to -12%
-12%

5. Monetary Costs of Winter Weather
20% of State Department of Transportation or Cabinet of Transportation’s budget is winter road maintenance
USA`s state and local agencies spend around 2.3 billion on treatment each year
Millions of dollars are spent on infrastructure damage
Potholes, cracks, bumps from Freeze Thaw Cycle
Distribution Companies lose 32.6 billion vehicle hours to winter weather and traffic delays caused by winter weather, which is about 2.2 billion to 3.5 billion dollars.

6. Treatment

7. Rock Salt Advantages Sodium Chloride
Breaks the bond between the ice, snow or sleet and the pavement
Lowers the freezing point of water
Advantages
Inexpensive
Effective
Available
Disadvantages
Does not work at low temperatures
Has an impact on the Environment
Corrosive

8. Sand Advantages Used in Reduce Salt Zones and during low temperatures
Inexpensive
Low Temperatures
Available
Disadvantages
It does not melt snow and ice
Blocks drainage
Has an impact on the Environment
Needs to be swept

9. Pre-Mix Advantages Mixture of Sodium Chloride and Calcium Chloride
Used in Reduce Salt Zones and low temperatures
Advantages
Lower impact on the environment
Low Temperatures
Disadvantages
Expensive
Needs to be stored in a dry space

10. Liquid Calcium Chloride
Attracts moisture, which allows it to release heat
Very effective if mixed with rock salt
Advantages
Effective Pretreatment
Low Temperatures
Disadvantages
Expensive
Needs to applied at the right time

11. Liquid Magnesium Chloride
Pretreatment
Keeps the snow and ice from sticking to the road.
Advantages
Low impact on the environment
Low impact on the equipment
Low Temperatures
Disadvantages
Expensive
Needs to applied at the right time

12. Procedure Pretreatment to the roads Let the storm start
Apply liquid salting methods
Applied at the right time
Rain can wash this off the road
Before the storm hits, not during or after.
Let the storm start
Plow and rock salt the roads.
Liquid salt reduces the snow and ice`s ability to stick to the road and/or has turned it into slush, which is easy to remove from the roads.
Snowplows push the snow to the side of the street.
The salt melts any ice or snow left behind and gives drivers traction when they are driving on the road.

13. Environmental Impact Reduced Salt Areas Corrosive Wetlands
Sources of Drinking Water
Groundwater recharge areas
Salt sensitive agricultural and vegetative areas
Corrosive
Damages vehicles, especially airplanes
Airports use liquid and solid treatments methods that adhere to SAE AMS 1435 and SAE AMS 1431, respectively
Sodium restricted diet

14. Types of Crashes Single Vehicle Bumper to Bumper
Occur because the driver loses control of the car and slips or slides off the road and/or into a fixed obstacle
Bumper to Bumper
Occur since the drivers are unable to stop in enough time or are unable to stop.
Sliding into an intersection
Occur because the driver is unable to stop and slides into the intersection.

15. Pedestrian Safety Sidewalks are slippery because of snow and ice
Sidewalks needs to be cleaned
Not cleaning sidewalks makes them slippery
Clear the snow from the sidewalk after the snow plows come though
Use salt on sidewalks

16. Cyclist Safety Bike Lanes need to be clean Bicycles are vehicles
Same problems as motor vehicles
Bicycles are vehicles
Cyclist running into an object or off the path
Cyclist crashing into a another bicycle or car
Cyclist sliding into traffic

17. Research Areas Effects of Weather on Surface Transportation System
Environmental friendly treatment
Relationship between Weather and Highway Performance
Design roads that minimize weather impact.

18. Driving Tips If you do not have to go out then do not go out
Wait for snow plows and salt trucks to complete their job
Drive slowly and carefully
Leave room between you and other vehicles
Use lower gear
Slow down at intersections
Brake gently
Steer in the direction you want your front wheels to go
Keep windshield, windows and mirrors clean
Be careful, alert and smart
Note, Lecturer is not responsible if you get into crash by following or not following these tips. The Driver is responsible for their own driving and its consequences.

19. References
"How do Weather Events Impact Roads" FHWA, Federal Highway Administration, February 25, 2014, April 6, m
"Winter Road Treatment & Snow Removal" MassDOT, Massachusetts Department of Transporation, Fe 2014, April 6, SnowIce/WinterRoadTreatmentSnowRemoval.aspx
"Driving Safety Tips" Weather Channel, The Weather Channel, LLC, 1995 to 2014 April 6, drivingsafetytips/snow.html

20. Questions?
Thank You