MDSS Stakeholder MeetingJune, 18 2003

1

COMPUTING A BETTER WAY TO PLOW IN NORTHEASTERN

MINNESOTA

Kwasi D. Amoah, Graduate Student, MSEM

University of Minnesota DuluthDepartment of Mechanical & Industrial Engineering

Northland Advanced Transportation Systems Research Laboratory

MDSS Stakeholder MeetingJune, 18 2003

2

Background

• Snowplow Operations & Resource Management (SORM)

• Funded through the Minnesota Department of Transportation (Mn/DOT) and the Center for Transportation Studies (CTS), University of Minnesota

• Focus on Winter Maintenance issues in District 1 of Mn/DOT

MDSS Stakeholder MeetingJune, 18 2003

3

Concerns

• Efficient and effective utilization of resources• Consistent service levels for roadways• Previous attempts in implementing route

optimization software by Mn/DOT failed • Federal Highway Administration’s development

of multi-state decision support system for winter road maintenance

MDSS Stakeholder MeetingJune, 18 2003

4

Goal• Develop a Management Planning

Tool (Decision Support System) using Discrete Event Simulation Modeling to assist in– Operations Improvement– Resource Utilization– “What-if” Scenarios

MDSS Stakeholder MeetingJune, 18 2003

5

Why Simulation?

• Complexity of operations cannot be modeled by analytical methods

• Provides a mechanism for developing and analyzing different scenarios

• Serves as a general management tool that can be modified to meet future needs

MDSS Stakeholder MeetingJune, 18 2003

6

Our Approach

• Work with Virginia, MN

• Select 5 routes on Highway 53 corridor

• Work with Area Superintendent, Supervisors and Drivers to understand operations

Virginia

Clean up

Post Plowing Operations•Dump Extra Sand and Salt•Refuel•Wash•Complete ODVI report

End of Storm?

Storm Arrives

Bare Lane?

Drivers arrive atMn/DOT in Virginia

Drivers completeOperators Daily Vehicle

Inspection Report

Plowing

Load Plowswith Sand & Salt

Fill Brine

No

End of Shift?Yes

No

No

Yes

Yes

Clean up completed?No Yes

Flow Process

Concept Map

Plow Speed

Traffic density

Visibility

SnowMoisture Content

Snow Depth

Time of Day

Pavement Temperatur

e

Air Temperature

Snow Accumulation Rate

Sun

Humidity

Wind Speed & Direction

Concept Map - Simplified

Pavement Temperature

Material Application

Plow Speed

Traffic density

Visibility

SnowMoisture Content

Snow Depth

Snow Accumulation Rate

Input Data Collection & Modeling

Data Collection• “Expert Opinion”

– Plow Speeds

• RWIS– Accumulation Rates– Moisture Content– Pavement

Temperature

• Virginia - Mn/DOT Guidelines– Material Application

Rates

Probability Density Functions

• Plow Speed– Triangular Distribution– Beta Distribution

• Accumulation Rates, Moisture Content and Pavement Temps– Fit distribution using RWIS

data

• Material Application Rates– Fit distribution using

historical application data from Mn/DOT

MDSS Stakeholder MeetingJune, 18 2003

11

Model Layout

MDSS Stakeholder MeetingJune, 18 2003

12

Start Simulation

MDSS Stakeholder MeetingJune, 18 2003

13

Model Design & Data Flow

Route Characteristics

Storm Characteristics

MS Excel VBA ProModel

Road Conditions

Output Data

Model Parameters Simulation ModelActiveXCOM

MDSS Stakeholder MeetingJune, 18 2003

14

Output

Summary Report: Route 201

Rural Commuter; Lane Miles = 81.92 Number of Replications = 5

Name Units Minimum Value Maximum Value Avg Value

Storm Start Time Minutes 0 0 0

Storm End Time Minutes 0 300 300.000

Time To Bare Lane Minutes 0 453.22 453.220

Time To Bare Pavement Minutes 0 284.29 284.290

Material Applied lbs 0 98304 98304.000

Material Cost $ 0 324.4 324.400

Labor Cost $ 0 321.13 321.130

MDSS Stakeholder MeetingJune, 18 2003

15

Conclusions

• The model adequately captures the plowing operation

• Initial Validation suggests that the model might be inadequate in predicting times to bare lane

• Validation will be an ongoing effort as more “accurate” data on the model parameters are obtained and as the scope of the model expands

• Verify Processing Logics & “Rules of Practice”• Model has capability of conducting “what-if”

scenarios to assist with operations improvement and resource management

• Continue to improve user interface

MDSS Stakeholder MeetingJune, 18 2003

16

Acknowledgements

Center for Transportation StudiesNorthland Advanced Transportation

Systems Research LaboratoryMinnesota Department of

TransportationUniversity of Minnesota DuluthFederal Highway Administration