HDM4 Applications

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HDM-4 Applications
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HDM-4 Applications

• Project Appraisal
• Project Formulation
• Maintenance Policy Optimization
• Road Works Programming
• Network Strategic Analysis
• Standards Policies

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Project Appraisal
Concerned with the economic justification of a
project defined by other means.

• Project types
• New construction, upgrading
• Reconstruction, resealing
• Widening, lane addition
• Economic indicators
• Net Present Value (NPV)
• Internal Rate of Return (IRR)

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Paving a Gravel Road
Current Policy (Without Project)
- Gravel resurfacing when thickness of gravel
is less than 50mm
- Routine maintenance
- Grading every 182 days
Gravel Road with300 AADT
Proposed Project (With Project)
- Upgrade the road to a paved standard
- After upgrading, routine maintenance,
patching 100 of the potholes, and resealing
when damaged area gt 20
Two Project Alternatives
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Roughness Progression
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Comparison of Alternatives

• Evaluation Period 20 years
• Discount rate 12.00
• ---- Present Values
  ---------------- Internal
  Construction Road
  Net Rate ofLength Maintenance
  User Total Present Return(km) Alt.
  Costs Costs Costs Value
  ()
• 10.0 Without 0.18 5.10
  5.28 With 1.75 3.10
  4.85 0.43 15.5

Is the project economically justified?
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Net Economic Benefits
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Project Formulation
Concerned with the economic comparison of project
alternatives to better define the project.

• Compares many project alternatives, e.g.
• Surface Types
• Surface Thicknesses
• Geometric standards
• Timing of intervention
• Compares alternatives in terms of net benefits
  and agency costs (economic efficiency frontier
  graph)

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Optimal Timing for Paving
- Regravel and grading every 182 days
- Upgrade in 2006
- Upgrade in 2007
Gravel Road with300 AADT
- Upgrade in 2008
- Upgrade in 2009
Many Project Alternatives
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Economic Efficiency Frontier
Which is the optimal alternative?
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Maintenance Policy Optimization
Concerned with finding an optimal maintenance
policy and funding for a given road class.

• User defines road classes in terms of condition
  and traffic
• A series of condition responsive road works are
  evaluated
• The alternative with highest NPV is identified
  along with the recurrent and capital resources
  needed to implement the alternative

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Asphalt Road Maintenance
- Reconstruction when roughness gt 8.0 IRI
- 25 mm reseal when damaged area gt 10
- 25 mm reseal when damaged area gt 20
- 25 mm reseal when damaged area gt 30
- 40 mm overlay when roughness gt 3.0 IRI
A Paved Roadin Fair Condition
- 40 mm overlay when roughness gt 4.0 IRI
- 40 mm overlay when roughness gt 5.0 IRI
- 80 mm overlay when roughness gt 3.0 IRI
- 80 mm overlay when roughness gt 4.0 IRI
- 80 mm overlay when roughness gt 5.0 IRI
- All include routine maintenance and patching
100 of potholes
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Roughness Progression
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Economic Efficiency Frontier
Which is the optimal maintenance policy?
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Road Works Programming
Concerned with the preparation of single or
multi-year road work and expenditure programmes
under specified budget constraints.

• Objective prioritise candidate road projects in
  each year within annual budget constraint
• Annual budgets obtained from strategic
  maintenance plan

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Procedure

• Use specified standards to screen network
  identify candidate projects, e.g.
• road sections which exceed specified condition
• roads with inadequate capacity
• pavements which need strengthening
• upgrade pavements with high traffic volumes
• Determine maintenance or improvement options
• Specify budget limits periods
• Optimise using selected objective
• Produce optimal list of projects for budget period

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Evaluation of Road Sections
Good Condition Roads- Reseal 25 mm in 2006-
Reseal 25 mm in 2007- Reseal 25 mm in 2008-
Reseal 25 mm in 2009
Homogeneous Road Sections

• Fair Condition Roads- Overlay 40 mm in 2006-
  Overlay 40 mm in 2007- Overlay 40 mm in 2008-
  Overlay 40 mm in 2009- Overlay 80 mm in 2006-
  Overlay 80 mm in 2007- Overlay 80 mm in 2008-
  Overlay 80 mm in 2009

• Poor Condition Roads- Overlay 80 mm in 2006-
  Overlay 80 mm in 2007- Overlay 80 mm in 2008-
  Overlay 80 mm in 2009- Overlay 100 mm in 2006-
  Overlay 100 mm in 2007- Overlay 100 mm in 2008-
  Overlay 100 mm in 2009

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Unconstrained Work Program
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Constrained Work Program
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Work Program Output
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Network Strategy Analysis
Concerned with the analysis of entire road
networks to determine funding needs and/or to
predict future performance under budget
constraints

• Objectives
• Determine budget allocations for road maintenance
  and improvement
• Prepare for work programmes
• Determine long term network performance
• Assess impact on road users

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Strategic Planning

• Forecast scenarios of revenues available budget
• Assess current condition of assets
• Forecast traffic demands (from road network plan)
• Evaluate impact of strategies on performance and
  costs - using predictive model
• Optimize strategies under alternative budget
  scenarios - maximize NPV for each scenario
• Determine multi-year program allocations
  performance

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Strategic Planning Approach
Matrix of Road Classes
G
F
P
A.C.
L
M
H
Road Network
Resource Constraints
ProgramwithoutBudgetaryConstraints
Optimal Program underBudgetary Constraints
OptimizationModule
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Diagnostic of the Network Condition
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Diagnostic of Road User Costs
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Diagnostic of Agency Costs
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Diagnostic of Road Classes
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Solution Catalog per Budget Level
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Consequences to Society
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Consequences to the Network
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Consequences to the Agency
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Consequences to the Users
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Support Definition of Budget Level
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Support for Allocation of Resources
Maintenance Budget (m)
Primary Roads Flexible Gravel
Secondary Roads Flexible Gravel
Region
34.5 21.8
North
45.9 18.7
East
34.6 13.5
24.9 11.8
South
52.1 21.0
45.0 21.8
27.2 20.4
19.5 12.3
West
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Optimal Budget Requirements
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Support for Programming of Works
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Standards Policies
Concerned with specific studies designed to
define rational technical standards and vehicle
policies

• Road pricing
• road use costs (to define fuel levies)
• congestion charges
• weight-distance charges
• Vehicle regulations
• axle load limits
• energy consumption, vehicle emissions noise
• Engineering Standards
• sustainable road network size
• pavement design and maintenance standards

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Technical Standards
400
300
200
What is the optimal traffic threshold for paving?
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Vehicle Policies
How much road damage is caused by trucks?