Overview of dTIMS Input, Analysis and Reporting HTC INFRASTRUCTURE MANAGEMENT LTD

Topics l Data Input l Models l Analysis l Reporting

Typical Times Spent on Different Phases of Analysis Establishing Reliable Input Data 40% Model Calibration 10% Treatments, Triggers and Resets 20% Running dTIMS 10% Verification of Output 20%

Importance of Data l Models are incremental l Predict the change in condition based on current condition l Existing condition-as defined by input data- is therefore critical for the short and medium-term predictions

Confidence in Predictions Over Time Time Condition Existing Condition Confidence Interval Trigger Interval Criteria for Intervention

Implications of Data on Predictions Trigger Interval Time Condition Existing Condition Confidence Interval Criteria for Intervention

Data requirements l Road Referencing l Traffic Characteristics l Pavement Properties l Pavement History l Road Condition l Strength You can use what you have to start

Data Sources l RAMM Database –Primarily from Treatment Length Table l Look up Tables –Mean Monthly Precipitation –Pavement Types l Default Values l User Input

Why do we convert the data? l dTIMS stores in fixed format dBase files l HDM models used –Condition descriptions differ from RAMM –Extra items needed that are not in RAMM l Some manipulation of triggers required outside dTIMS

Converting Data RAMM Database dT2699 Strength Program Other Data Interface Program

Example of Cracking Conversion

RAMM Rut Depth Conversion Problems

Pavement Strength RAMM Database dT2699 Strength Program Other Data Interface Program

Pavement Strength l Can be one of the more important pavement deterioration modelling parameters l Analysis uses SNP: Structural Number of the Pavement

Available Methods l FWD with Layer Thickness l FWD without Layer Thickness l CBR Layers l Benkelman Beam l ARRB Pavement Capacity l Typical Pavement Designs

Topics l Data Input l Models l Analysis l Reporting

Road Deterioration in HDM-III l Bituminous and unsealed pavements l Pavement strength - modified structural number l Cracking initiation and progression l Ravelling initiation and progression l Potholing initiation and progression l Rutting l Roughness

New Deterioration Models in HDM-4 l Extended to more pavement types including Concrete l Pavement strength - routine maintenance effects l Reflection of structural cracking l Transverse thermal cracking l Plastic flow component of rutting l Surface texture

Status of HDM-4 Models l New models mainly conceptual and default coefficients lack validation l Models not yet fully documented - exist only in ISOHDM working papers l Some will probably be modified in future releases of HDM-4 software

What Models are We Using? l Pavement deterioration –HDM-III models plus maintenance cost, SFC, texture –Later HDM-4 where applicable l Road user effects –PEM based l Maintenance effects

dTIMS Pavement Models l Have mainly implemented modified HDM-III for Phase I l Predicting –Cracking –Potholing –Roughness l Based on other research (Opus) –Texture –SCRIM

Opus Preliminary NZ Calibration l Some indication that HDM crack initiation is valid l Ravelling requires a surface defects indicator as proposed for HDM-4 l Roughness progression is faster due to environmental effects l RAMM data generally inadequate for reliable calibration l Long term pavement performance sections should be established for proper calibration

Influence of Calibration Pavement age (Years) Roughness IRI Un-calibratedCalibratedActual l Short-term negligible - existing condition critical l Long-term significant

Implications of Data on Predictions Trigger Interval Time Condition Existing Condition Confidence Interval Criteria for Intervention

Topics l Data Input l Models l Analysis l Reporting

Analysis Process STANDARDS POLICY BUDGET STANDARDS COMPLIANCE YES EXECUTE ! NO !! FIND ALTERNATIVES !! Increased Budget ! Adjust Standards ! Adjust Network Size ! NETWORK OR...

Cost Benefit l Objective Function –Maximise Area under Curve –Minimise Total Transportation Cost –Maximise Savings in VOC

Area Under Curve (AUC) Composite Index Time Analysis Period Strategy Do-nothing Benefit

Minimise Total Transportation Cost (TTC) MAINTENANCE LEVEL COSTS Total Transport Costs Road User Costs Maintenance Costs Construction Costs Optimum Maintenance

Vehicle Operating Costs l Based on PEM roughness/VOC functions l Give economic costs due to roughness l In Phase II will consider including volume-to- capacity ratio and delay costs

Maximise Saving in VOC Time Analysis Period Strategy Do-nothing VOC Benefit

Objective Function To Use Objective Function Area Under Curve Total Transportation Costs Vehicle Operating Costs Application Example Const. Budget Poor Roads Med. Budget Poor Roads Adeq. Funding Good Roads

Selection of Strategies (Efficiency Frontiers) Benefits Costs IBC Costs B A

Treatment Strategies l Defined by the type and timing of a Rehab Treatment e.g. –Reconstruct in 2000; or –Overlay in 2001 l Strategy includes the Rehab and the later Periodic Treatments plus Routine l “Do-nothing” is also a Strategy - the base case

Triggers for Performance Standards l Strengthening –Maintenance Cost –Granular Overlay Need (GOVL) –Roughness l Smoothing –Roughness –Rutting –Cracking

Triggers for Performance Standards (Cont.) l Resurfacing –Surface Integrity Index (SII) –Texture Depth –Friction –Max. Roughness

Optimisation l Budget Scenarios

Steps in Repetitive Analysis l Create dTIMS Input File l Update Treatment Costs (Interface) l Change Analysis Period l Generate Strategies l Optimisation l Adjust Program l Generate Reports

Topics l Data Input l Models l Analysis l Reporting

Views in dTIMS l Inventory Data Base l Budget Scenario Summary l Strategy List l Condition Distribution l Analysis Set Summary l Maintenance Program l Performance Graphs (6)

Reporting cont.. l Reporting from dTIMS limited and not flexible - we fixed this!!!! Analysis Network Project Reporter Porgram