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An Integrated GIS approach to Municipal Pavement Management

Presented By:

Jeff Steele, City of Greensburg

Michael Bieberitz, GISP, HNTB Corporation

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Intro

Here’s the Problem:

The city of Greensburg Streets Department needed a way to:

• Determine if the same streets were being paved more often than necessary.

• Track historic project and material costs.

• Estimate future project costs from assumptions based upon user input.

(currently, this is done manually through a paper-based system.)

An Integrated GIS approach to Municipal Pavement Management

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GLANCE+

City has a great GIS resource in use by some of other departments called

GLANCE+

Already in use by the city departments for several purposes

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GLANCE+

Sanitary

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GLANCE+

Water Utilities

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GLANCE+

Stormwater

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Is there a way to adapt existing technology for new uses?

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The Challenge

• Develop a way to display and track projects from many years that can exist on the same piece of pavement.

• Use existing GIS layers wherever possible.

• Incorporate new street application into existing GLANCE+

The Challenge

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The Challenge

• Challenge: How do we get so many projects to live on the same piece of road?

– Data Storage

– Display

• Solution: cross-reference table.

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TheChallenge

• Challenge: Greensburg centerline file

– Street segments generally stretch from intersection to intersection.

– City discovered that many past projects didn’t extend entirely from intersection to intersection. How do we get an accurate cost estimate?

• Solution: split lines into smaller segments.

What We Learned Along the Way

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The Challenge

• Challenge: Splitting segments causes other problems.

– Sometimes the entire segment is already part of another project.

• Solution: Track split segments so they can be related to each project.

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The Solution

What Does the application Look Like?

• Select road segments on a map

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The Solution

• Enter a few variables:

– Width

– Asphalt Cost

• Historic prices of asphalt are also kept.

– Utilities that could affect project costs

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The Solution

•Form returns values for

– Estimated tonnage

– Estimated tack cost

– Estimated total cost

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Results

• City entered projects from last five years to test accuracy of the product

• Actual cost and tonnage of material used versus what software estimated

• 130 projects completed between 2000 and 2005

Results

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Results

Actual vs Estimated Project Cost

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Actual vs Estimated Tonnage Used For Each Project

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age Actual

Estimate

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Results

• Average Tack Coat Tonnage Used:

– Estimated: 234.08

– Actual: 221.90

– Difference: +12.18

– % Difference: 5.4%

• Average Project Cost:

– Estimated: $8605

– Actual: $8095

– Difference: +$510

– % Difference: 6.3%

Summary Results for all 130 Projects

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Results

• Findings:

– Costs are a little inflated because centerline file stretches from center of intersection to center of intersection.

– Projects are usually edge to edge, so we overestimate by about 5%.

– Only 17 segments of road (totaling 1.22 miles) were paved more than once in the last five years.

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Questions