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HDM-4 CONFIGURATION

HDM-4 CONFIGURATION. PURPOSES. Customising data sets to reflect local circumstances Managing aggregate data Managing HDM-4 default data. COMPONENTS. Climate zones Road network data Road class Speed-flow types Traffic flow pattern Aggregate variables Default data Currency.

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HDM-4 CONFIGURATION

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  1. HDM-4 CONFIGURATION

  2. PURPOSES • Customising data sets to reflect local circumstances • Managing aggregate data • Managing HDM-4 default data

  3. COMPONENTS • Climate zones • Road network data • Road class • Speed-flow types • Traffic flow pattern • Aggregate variables • Default data • Currency

  4. CLIMATE ZONES • Climate has significant impact on pavement deterioration • Climatic conditions affect vehicle operation (e.g., rolling resistance, cold engine start, etc.) • Definition is based on moisture classification and temperature regimes • Number of climate zones are defined by the user

  5. MOISTURE CLASSIFICATION • Arid: very low rainfall, high evaporation, annual precipitation (AP) < 300 mm • Semi-arid: low rainfall, AP 300 ~ 800 mm • Sub-humid: moderate rainfall or strongly seasonal rainfall, AP 800 ~ 1600 mm • Humid: moderate warm seasonal rainfall annual precipitation 1500 ~ 3000 mm • Per-humid: high rainfall or very many wet-days, AP > 2400 mm

  6. TEMPERATURE CLASSIFICATION • Tropical: warm temperatures within a small range (20 ~ 35 ºC) • Sub-tropical-hot: high day, cool night temperatures, hot/cold seasons, (-5 ~ 45 ºC) • Sub-tropical-cool: moderate day temperatures, cool winters, (-10 ~ 30 ºC) • Temperate-cool: warm summer, shallow freeze (-20 to 25 ºC) • Temperate-freeze: cool summer, deep freeze winter (-40 to 20 ºC)

  7. CLIMATE DATA • Moisture-class related data: • Mean monthly precipitation (mm/year), Thorntwaithe moisture index • Duration of dry season (as a proportion of a year) • Temperature-class related data: • Mean annual temp, temp range ºC • Number of days with temp exceeding 32 ºC, freezing index, etc.

  8. ROAD NETWORK DATA • Road class • functional hierarchy to facilitate management or analysis of the road network • Speed-flow types • models the effects of traffic volume on speed and the economic consequences of road improvements • Traffic flow pattern • models traffic congestion at different hours of the day, and on different days of the week and year • Aggregate data (defaults) • pavement condition, strength, road geometry, etc.

  9. SPEED- FLOW MODEL Speed (km/hr) S1 S2 S3 Sult Flow PCSE/h Qnom Qo Qult

  10. DEFINING A SPEED-FLOW TYPE • Name • Road type • Ultimate capacity (Qult) in PCSE/lane/h • Free flow capacity as a proportion of Qult • Nominal capacity as a proportion of Qult • Jam speed at capacity in km/h

  11. TRAFFIC FLOW PATTERN Flow Periods Peak Next to Peak Medium flow Next to Low Low/Overnight Number of Hours in the Year Flow

  12. DEFINING TRAFFIC FLOW PATTERNS • Name • Road use • Number of flow-frequency periods • Number of hours in each flow-frequency period (HRYRp) • Percentage of AADT in each flow-frequency period (PCNADTp), or • Hourly flow in each period (HVp) as a proportion of AADT

  13. AGGREGATE DATA User defined • Traffic levels: e.g., low, medium, high. • Geometry class: in terms of parameters reflecting horizontal and vertical alignment • Pavement characteristics: structure and strength parameters defined according to pavement surface class • Road condition: ride quality, surface distress and surface texture • Pavement history: construction quality, pavement age, etc.

  14. DEFINING TRAFFIC BANDS • Defined by: • Description e.g., high, medium, low • Pavement surface class (e.g., bituminous, concrete or unsealed) • Mean AADT • Unlimited number of traffic bands

  15. DEFINING A ROAD GEOMETRY CLASS • Defined by : • Description e.g., mostly straight and gently undulating, bendy and winding, etc. • Average rise plus fall (m/km) • Average number of rises and falls (no./km) • Average horizontal curvature (deg/km) • Average super-elevation (%) • Other speed related data (e.g., speed limit) • Unlimited number of geometry classes

  16. BITUMINOUS PAVEMENT STRENGTH • Defined in terms of the structural adequacy to carry traffic loading • Structural adequacy • defined in qualitative bands e.g., good, fair, poor • each band is assigned a representative SNP • default pavement layer thickness for each band

  17. BITUMINOUS PAVEMENTS - LAYER THICKNESS • Method 1: • Define several ranges of SNP values • For each range and for each pavement type define HSNEW, HSOLD, HBASE • Specify default surface material for each surface type (i.e., AM or ST), and resilient modulus for stabilised road base type • Method 2 (HDM-4 Default): • Layer thickness derived using pre-defined range of SNP values, layer strength coefficients for surfacing and base material, and subgrade CBR of 8%

  18. CONCRETE PAVEMENTS • Structural adequacy is based on the pavement characteristics and traffic level • For each structural adequacy and traffic band, define slab thickness and: • Modulus of rupture (MPa) for • Jointed Plain concrete pavement (JPCP) • Percentage of steel reinforcement for • Jointed Reinforced (JRCP) and Continuously Reinforced (CRCP) concrete pavements

  19. UNSEALED ROADS • Requires detailed data on surfacing and subgrade material: • Gradation - maximum particle size, and percent passing 2.0, 0.425 and 0.075 mm sieves • Plasticity index • Structural adequacy and surface condition are related to the traffic level and are represented by the thickness of the surfacing material (gravel)

  20. ROAD CONDITION Aggregated into 3 measures: • Ride quality - an indication of the roughness of the road • Surface condition - modelled by a number of distress modes depending on the pavement type • Surface texture - gives an indication of texture depth and skid resistance of the surface

  21. RIDE QUALITY • An important parameter for: • Indicating road condition and maintenance needs • Predicting vehicle operating cost • For each road surface class define the number of bands e.g., good, fair, poor, bad • For each band define the mean roughness value, IRI (m/km)

  22. SURFACE CONDITION • Defined by an aggregate measure representing several distress modes • For each road surface class define the bands e.g., new, good, fair, poor, bad • Define mean values of the relevant distress modes e.g., cracking, ravelling, potholing, etc. for bituminous pavements

  23. SURFACE TEXTURE • Defined by a qualitative measure that gives an indication of the texture depth and skid resistance • For bituminous pavements, define the bands e.g., good, fair, slippery • For each band, and for each of the road surface types AM or ST, assign mean values of the sand patch texture depth and skid resistance at 50 km/h (SCRIM)

  24. CONSTRUCTION QUALITY • User defined bands such as good, fair, poor • For each band, define • construction defect indicator for bituminous surfacing (CDS), • construction defect indicator for roadbase (CDB), • relative compaction (COMP) • For unsealed roads, construction method is either ‘mechanical’ or ‘manual’

  25. CURRENCY • Defined in terms of: • Name (e.g., Dollars) • Symbol (e.g., $) • Symbol position (i.e., before or after the figures) • ‘Thousand’ separator (e.g., comma or point) • Unlimited number of currencies

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