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HDM-4 Applications. HDM-4 Applications. Project Appraisal Project Formulation Maintenance Policy Optimization Road Works Programming Network Strategic Analysis Standards & Policies. Project Appraisal. Project types New construction, upgrading Reconstruction, resealing
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HDM-4 Applications • Project Appraisal • Project Formulation • Maintenance Policy Optimization • Road Works Programming • Network Strategic Analysis • Standards & Policies 2
Project Appraisal • Project types • New construction, upgrading • Reconstruction, resealing • Widening, lane addition • Economic indicators • Net Present Value (NPV) • Internal Rate of Return (IRR) Concerned with the economic justification of a project defined by other means. 3
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 > 20% Two Project Alternatives 4
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? 6
Project Formulation • 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) Concerned with the economic comparison of project alternatives to better define the project. 8
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 9
Economic Efficiency Frontier Which is the optimal alternative? 10
Maintenance Policy Optimization • 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 Concerned with finding an optimal maintenance policy and funding for a given road class. 11
Asphalt Road Maintenance - Reconstruction when roughness > 8.0 IRI - 25 mm reseal when damaged area > 10% - 25 mm reseal when damaged area > 20% - 25 mm reseal when damaged area > 30% - 40 mm overlay when roughness > 3.0 IRI A Paved Roadin Fair Condition - 40 mm overlay when roughness > 4.0 IRI - 40 mm overlay when roughness > 5.0 IRI - 80 mm overlay when roughness > 3.0 IRI - 80 mm overlay when roughness > 4.0 IRI - 80 mm overlay when roughness > 5.0 IRI - All include routine maintenance and patching 100% of potholes 12
Economic Efficiency Frontier Which is the optimal maintenance policy? 14
Road Works Programming • Objective: prioritise candidate road projects in each year within annual budget constraint • Annual budgets obtained from strategic maintenance plan Concerned with the preparation of single or multi-year road work and expenditure programmes under specified budget constraints. 15
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 16
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 17
2003 2003 2003 2003 2003 2004 2004 2004 2005 2005 2005 Work Program Output 20
Network Strategy Analysis • Objectives: • Determine budget allocations for road maintenance and improvement • Prepare for work programmes • Determine long term network performance • Assess impact on road users Concerned with the analysis of entire road networks to determine funding needs and/or to predict future performance under budget constraints 21
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 22
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 23
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 34
Standards & 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 Concerned with specific studies designed to define rational technical standards and vehicle policies 37
Technical Standards 200 300 400 What is the optimal traffic threshold for paving? 38
Vehicle Policies How much road damage is caused by trucks? 39