2. Maintenance Decision Support System

3. Intersection I-15 Intersection I-15 and I-70 in Utah and I-70 in Utah Point intervals Point intervals along corridor along corridor ranging from 1 ranging from 1 to 3 miles to 3 miles Intersection I-15 Intersection I-15 and I-70 in Utah and I-70 in Utah Point intervals Point intervals along corridor along corridor ranging from 1 ranging from 1 to 3 miles to 3 miles GIS Display of Jurisdiction Area

4. Snow Rain Mixed Midnight Wednesday Midnight Tuesday Midnight Thursday 0.00 0.10 0.20 0.30 0.40 Precipitation Rate (SWE) (in/hr) Two-Day Precipitation Rate History Prediction Point #3 36912151821242730333639424548 Time Since Awareness (hrs) 0 0.05 0.15 0.25 0.35

5. 5 10 15 20 25 30 35 40 Temperature (deg F) 36912151821242730333639424548 Time Since Awareness (hrs) 0 0 Two-Day Temperature History Prediction Point #3 Midnight Wednesday Midnight Tuesday Midnight Thursday Pavement Temperature Air Temperature

6. Midnight Wednesday Midnight Tuesday Midnight Thursday Two-Day Snow Depth History Without Treatment Prediction Point #3 2 4 6 8 10 12 14 16 Snow Depth (in) 36912151821242730333639424548 Time Since Awareness (hrs) 0 0 Snow Depth with No Maintenance Efforts

7. Midnight Wednesday Midnight Tuesday Midnight Thursday Two-Day Chemical Concentration History Without Treatment Prediction Point #3 Concentration (% by weight) 5 10 15 20 25 36912151821242730333639424548 Time Since Awareness (hrs) 0 0 Concentration of NaCl (no treatment)

8. Midnight Wednesday Midnight Tuesday Midnight Thursday Two-Day Friction Coefficient History Without Treatment Prediction Point #3 Friction Coefficient 36912151821242730333639424548 Time Since Awareness (hrs) 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Friction Coefficient with No Maintenance Efforts

9. What ? When ? How ?

10. Decisions Supported by MDSS 2.1 become aware of weather threat 2.2 monitor weather threat 2.3 identify weather threat occurance 2.4 assess sufficiency of equip. & consumables 2.6 check readiness of equip. & consumables 2.10 assign minimum staff to monitor and manage 2.13 disseminate important weather info to field staff 2.14 forward-place equipment and stocks 2.16 alert supervisory staff to monitor/prepare 2.18 alert crews

11. Decisions Supported by MDSS 2.21 select treatment expendables 2.5 replenish consumable stocks 2.7 mix expendables 2.11 select event-treatment strategy 2.17 confirm strategy-plan in place 2.12 assign crews to shifts, schedules 2.22 dress and load equipment 2.19 split crew shifts 2.25 dispatch crews to treat (anti-ice)

12. Decisions Supported by MDSS 2.24 dispatch crews to wait at routes 2.27 dispatch crews to treat (plow/spread) 2.28 dispatch crews to treat (plow cake, de-ice) 2.30 dispatch crews to treat (ice-spot treat) 2.42 re-evaluate storm intensity and duration 2.44 determine the LOS goal is reached 2.39 close roads 2.41 rest crews

13. Decisions Supported by MDSS 2.29 dispatch crews to treat (bulk removal) 2.31 dispatch crews to treat (drifting) 2.47 dispatch crews to clean up 2.43 identify threat end 2.48 open roads

14. Pre-Defined Levels Of Service ● DOT road classifications based on number of vehicles/day ● Level of Service standards Bare Pavement Full-width 50%-75% width Left-wheel Passing Lane None Time 4, 6, 16, 24 hours after storm ends Or as soon as practical and as weather permits ● “Provide reasonable traveling conditions for the prudent driver during storm, depending on location, time of day”

15. Current Pavement Temperature (F) Anticipated Pavement Temperature Change Precipitation Type* / Severity Salt Application Rate ** (lbs per two-lane mile) Comments Above 32 25 to 32 20 to 25 15 to 20 15 or Below Higher Lower Higher Lower Higher Lower Higher Lower R, SL, WS / Light R, SL, WS / Mod. - Heavy FR, SL, DS, WS / Light FR, SL, DS, WS / Mod. – Heavy FR, SL, DS, WS / Light FR, SL, DS, WS / Mod. - Heavy SL, DS, WS / Light SL, DS, WS / Mod. – Heavy SL, DS, WS / Light SL, DS, WS / Mod. - Heavy SL, DS / Light SL, DS / Mod. – Heavy SL, DS / Light SL, DS / Mod. - Heavy 100 to 200 200 to 300 200 to 400 300 to 500 400 to 600 500 to 700 700 to 800 No Salt. Apply Sand and Plow as Needed. Use Pre-Wet System Pre-Wet: 6 Gallons/Ton Pre-Wet: 8 Gallons/Ton Pre-Wet: 10 Gallons/Ton Monitor Pavement Temp. Switch to Salt if Rising Above 15F * R=Rain, FR=Freezing Rain, SL=Sleet, WS=Wet Snow, DS=Dry Snow If snow is blowing off roadway and no hard-pack exists, do not apply chemicals or abrasives. ** Initial application. Plow and re-apply salt at half-rate if surface becomes mealy or slushy, or full rate if glazed or packed. Maine DOT Application Rate Matrix

17. Snow Rain Mixed Ideal Time For Chemical Application Ideal Time For Plowing Effort Midnight Wednesday Midnight Tuesday Midnight Thursday 0.00 0.10 0.20 0.30 0.40 Precipitation Rate (SWE) (in/hr) Two-Day Decision Support History Recommended Treatments Prediction Point #3 36912151821242730333639424548 Time Since Awareness (hrs) 0 0.05 0.15 0.25 0.35

18. Midnight Wednesday Midnight Tuesday Midnight Thursday Two-Day Snow Depth History With and Without Treatment Prediction Point #3 2 4 6 8 10 12 14 16 Snow Depth (in) 36912151821242730333639424548 Time Since Awareness (hrs) 0 0 Snow Depth with No Maintenance Efforts Snow Depth with Recommended Maintenance Efforts

19. Midnight Wednesday Midnight Tuesday Midnight Thursday Two-Day Chemical Concentration History With and Without Treatment Prediction Point #3 Concentration (% by weight) 5 10 15 20 25 36912151821242730333639424548 Time Since Awareness (hrs) 0 0 Concentration of NaCl (no treatment) Concentration of NaCl (with treatment)

20. Midnight Wednesday Midnight Tuesday Midnight Thursday Two-Day Friction Coefficient History With and Without Treatment Prediction Point #3 Friction Coefficient 36912151821242730333639424548 Time Since Awareness (hrs) 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Friction Coefficient with No Maintenance Efforts Friction Coefficient with Recommended Maintenance Efforts LOS 1

21. What A Tool !