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ROAD MANAGEMENT. A Framework for Sustainable Road Management. THE MANAGEMENT FUNCTIONS. Planning Setting aims and objectives Determining standards and policies Estimating long term expenditure Programming Medium term work programmes Preparation Detailed project design and work packaging
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ROAD MANAGEMENT A Framework for Sustainable Road Management
THE MANAGEMENT FUNCTIONS • Planning • Setting aims and objectives • Determining standards and policies • Estimating long term expenditure • Programming • Medium term work programmes • Preparation • Detailed project design and work packaging • Operations • Implementation of works in field
THE MANAGEMENT CYCLE Aims Audit Needs DATA Implem. Actions Cost/Pr
DECISION SUPPORT ACTIVITIES • Assess Needs • Road inventory • Condition and traffic assessment • Condition and traffic projection • Determine Actions • Apply standards • Identify and select treatments • Estimate Quantities and Costs • Assign Priorities under Budget Constraints • Analyse Past and Future Trends
QUESTIONS • What is essential to support the TASKS? • What constraints may exist in assessing needs, and how might you address them? • How might you best deploy your limited resources?
DATA DESIGN ISSUES • RELEVANCE • Only collect items of direct relevance on OUTPUTS and DECISION MAKING today • Adopt standard units and dimensions • APPROPRIATENESS • Choose a strategy based on intended use, eg. network or project level planning, design, etc. • RELIABILITY • Choose a level of precision depending on application. Data to be sufficiently accurate, complete and up to date. • AFFORDABILITY • The quantity and quality of all data must be affordable in resource terms and costs effective in decision making terms.
AIMS AND OJECTIVES • AIMS - To encourage a structured approach to the selection of key data and models to support cost effective decision making • OBJECTIVES - To increase knowledge and skills in the identification of key data items, model calibration and strategies for collection and application.
SCOPE • Reliability of results • Application of results • Calibration focus • RUE/RDWE calibration • Calibration levels • Reliability concepts • What to focus on • Information Quality Levels
Calibration Focus • Road User Effects • The models must predict the correct magnitude of costs and relativity between components • Road Deterioration and Works Effects • The models must reflect local pavement deterioration rates and maintenance practices/effects
RDWE CALIBRATION IN ZIMBABWE • Roughness Progression • Crown height (and earthworks quantities) • Drainage quality • Design standard • Unstable subgrades (Expansive and Dispersive) • Crack initiation and progression • Design standard • Original surfacing (single or double) • Reseals
Calibration/Adaptation Activities- RD Model Calibration CRPCDS dACW = Kcpw zw [(zw a1 a2tW YE4 (SNPa3) + SCWa4 )1/a5 - SCW] Calibration Factor Model Coefficients
Calibration Levels • Level 1: Basic Application • Addresses most critical parameters • ‘Desk Study’ • Level 2: Calibration • Measures key parameters • Conducts field surveys • Level 3: Adaptation • Major field surveys to requantify fundamental relationships
Bias and Precision • Only way of assessing model’s reliability is by comparing its predictions to known data • Need to take into account two considerations: • Bias • Precision
Correction Factors • Used to correct for bias • Two types of factors • Rotation (CF = Observed/Predicted) • Translation (CF = Observed - Predicted) • Translation factors shift the predictions vertically; rotation factors adjust the slope
RDWE Calibration - 1 • Simulation of Past • take sample of roads with historical data (traffic, design, etc.) • simulate deterioration from construction to current age • compare results • Average predicted condition should be similar to current condition
Road User Effects • Some data available from field studies; other from controlled experiments • Can verify using tariff surveys
What to Focus On • HDM-III had about 80+ data items and model parameters; HDM-4 over 100 • To assist users, conducted sensitivity tests and defined ‘impact elasticities’ • Grouped data into ranges
IQL Levels • IQL - 1: Fundamental Research • many attributes measured/identified • IQL - 2: Project Level • detail typical for design • IQL - 3: Programming Level • few attributes, network level • IQL - 4: Planning • key management attributes • IQL - 5: Key Performance Indicators