because of small scale features like snow bands and rush hour issues. He
described a case where the MDSS had a total forecast of 700 tons of salt
predicted. He estimated that they used around 725 tons during the storm. He
indicated that he was impressed with its recommendations this year.
During the January 29-30, 2004 storm, they wanted to experiment on one route by
applying exactly what the MDSS forecast. For the 17 miles on IA route 415, they
followed the guidance and in 3 (or 4) passes dropped 24 tons of salt at the times
recommended by MDSS. Upon inspection of the road after the treatment, it was
deemed to be "perfect".
Overall, the system is somewhat conservative on early snow projections and on
material rates. He has found the precipitation ending time to be very good.
The rules of practice need to be modified to take into account the time of day and
direction (inbound vs outbound) during rush hours. A prediction of 200 lbs/lane
mile will be increased to 350 lbs/lane mile during rush hours because it will take
the trucks longer to complete a route.
Was comfortable with the changes recently made to make the blowing snow
algorithm more sensitive.
He and his staff trusted the system much more for reference this year. It appears
that the system is better within 12 hours of a storm than in the 12-24 hour
planning stage. This may be due to the loss of the mesoscale models after that
period.
Indicated that the road temperature predictions were much better this year.
The most important forecast of the day is from noon to 3 PM for crew scheduling.
Successfully used the "what if" scenario generation function to create treatment
plans.
Rich Hedlund - Garage Supervisor, Des Moines West, IADOT (Feb 25, 2004)
Because Rich was not involved in the verification program this year, he did not
routinely use the system, but his sense was that it was more complete and
accurate. It was mainly used to plan for upcoming storms.
The lack of consistent bandwidth at this garage (due to line sharing) made using
the MDSS more difficult.
Was comfortable with the changes recently made to make the blowing snow
algorithm more sensitive and wished the MDSS had a road/bridge frost product.
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