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Local Calibration of the MEPDG Using Pavement Management Systems

Chapter 7. Database Verification

Introduction

The overall success of this project is in large part linked to the successful completion of the verification process. Several forms of coordination were conducted with NCDOT to ensure data quality and applicability to MEPDG calibration. As NCDOT populated the MEPDG calibration database, the APTech team contacted the NCDOT staff to discuss progress approximately every two to three weeks. The APTech team worked with the NCDOT staff to verify that proper procedures were being followed for storing the data, ensuring that the framework was being tested and any problems with the framework were identified and adjusted. Specifically, the following details were confirmed with NCDOT:

  • Are all the data items that were specified in the framework being collected or are plans in place for collecting any missing data?
    • To minimize variability (e.g., construction, pavement performance, traffic loadings), pavement projects were selected from the North Carolina interstate and/or primary system.
    • Climate stations currently contained within the MEPDG was used for all selected pavement sections.
    • Pavement condition assessment is based on the NCDOT pavement condition definitions, which is not necessarily based on the LTPP Distress Identification Manual, as recommended in the MEPDG documentation. NCDOT pavement condition assessment is shown in table 33 and Appendix B (flexible survey manual) and Appendix C (rigid survey manual).
Table 33. NCDOT pavement distress types.
Flexible Pavement Rigid Pavement
Alligator cracking Cracking
Transverse cracking Corner breaks
Rutting Joint seal damage
Raveling Spalling of joints
Bleeding Shoulder drop-off
Patching Patching
Oxidation
  • Have the data gone through the required quality control procedures to verify their correctness, accuracy, and reliability? If not, what procedures will be used to verify the accuracy of the data?
    • NCDOT assured that all the data incorporated into the MEPDG calibration database had received the necessary quality control checks to ensure data accuracy.
  • Does the data cover all the three typical pavement types, including both new design and rehabilitation activities? Are all distress types represented?
    • Since the NCDOT highway network is comprised of primarily HMA pavements, with a lower percentage of portland cement concrete (PCC) pavements, only project data for these two pavement types was provided. In addition, the MEPDG calibration database contains several HMA pavements that have received an HMA overlay.
  • Can the data from various sources be integrated in a single database so that performance data can be linked to material, traffic, construction, and climatic data and can the data be easily extracted for use in calibrating the models?
    • NCDOT stated that all the necessary data was available, though not necessarily contained within one database or possibly in electronic format. NCDOT worked with other divisions (e.g., Materials, Construction, and Traffic) to obtain the necessary data. In addition, much of the available materials information was assembled into a database by the North Carolina State University (NCSU) as part of a NCDOT sponsored research project. NCDOT obtained the NCSU database and transferred the data into the MEPDG calibration database.

The final verification activity was conducted to ensure the data provided by the state appeared reasonable. Although it is difficult for the APTech team members to check the validity of the data, reasonableness checks were used to determine the overall soundness of the data. Distress data was compared to the construction data to verify that the level of deterioration was reasonable for the specific pavement design and age. Similarly, material test results were reviewed to check that they are within reasonable ranges of acceptance. From this review, the APTech team determined that the data provided by NCDOT appeared to be reasonable.

Project Selection

As previously described, NCDOT selected pavement sections for use in the calibration process based on representative pavement structural section, section uniformity (e.g., pavement type, pavement thickness, materials), and availability of traffic, material, and pavement performance data. As outlined in the NCHRP 1-40B report (NCHRP 2004) the minimum number of total pavement sections, by distress, that should be selected for performance prediction model calibration includes (see table 34): The research team recommended that NCDOT preferably select 20 to 30 pavement sections, for each pavement type, to be used in the calibration process. NCDOT stated that they would do their best to comply with this request, but also noted finding this number of sections, especially for the PCC pavement sections, may be challenging.

Table 34. Minimum sample size for MEPDG calibration.
Distress Minimum number of roadway segments
Total rutting or faulting 20
Load related cracking 30
Non-load related cracking 26
Reflection cracking (HMA surfaces only) 26

MEPDG Calibration Database

In March 2009, the APTech team delivered a preliminary MEPDG calibration database to NCDOT for data population. As part of this process, NCDOT was also asked to evaluate and comment on the application of the MEPDG calibration database to meet the data requirements. In addition, NCDOT was asked to provide any additional information that was needed for operation of the MEPDG calibration database by the APTech team. The following provides a summary of comments received from NCDOT on the MEPDG calibration database.

  • The preliminary MEPDG calibration database was developed using MS Access 2003®; however, NCDOT is currently using MS Access 2007®. NCDOT updated the MEPDG calibration database to the newer version of MS Access.
  • The MEPDG calibration database contains thirty-one NCDOT projects consisting of a mix of older asphalt, newer asphalt, rehabilitated/resurfaced asphalt, and JPCP. The listing of projects, according to pavement type, is shown in table 35.
Table 35. Projects by pavement type.
Pavement Type No. of Projects
New asphalt (constructed in1993) 9
New asphalt (constructed in 1999) 10
Asphalt (thin layer thickness) 3
Asphalt (overlay projects) 3
Concrete 6
  • NCDOT developed and provided to the APTech team all of the MEPDG project files (*.DGP) for each project identified in table 34. These files allowed the project team the ability to verify or clarify the project input data as needed.
  • NCDOT also provided the APTech team all climate files (*.HCD) for the state of North Carolina. The climatic files were generated for all identified projects based on the latitude and longitude of the projects midpoint location. Hourly climate data was unavailable and therefore excluded from the MEPDG calibration database.
  • Upon review of the Highway Construction and Materials System (HiCAMS), it was discovered that much of the detailed construction and material data had been deleted three years after project completion for the majority of the projects; this is especially true for the concrete pavement projects. Though this data may be available in other NCDOT paper records, it was determined that it would require an unreasonable time commitment to obtain these files for this project.
  • NCDOT determined that the MEPDG calibration database template originally provided by the APTech team was not conducive to data entry and did not adequately follow relational database design. All database fields were set to integer values, where many of the inputs also included text or decimal fields. Significant time was required to modify and improve the MEPDG calibration database to meet NCDOT data entry and relational database design requirements. The modified MEPDG calibration database by any means is not perfect; ideally NCDOT would like to have coded a few behaviors in that would have simplified the data entry and viewing process.
  • NCDOT populated the MEPDG calibration database with the best available pavement condition data.
  • Water table data is not available and therefore was not included in the MEPDG calibration database.
  • Based on the work conducted for this project, NCDOT is discussing the possibilities of capturing additional materials data in the pavement management system. Currently, NCDOT only captures mix type and depth of each layer.
  • Asphalt design files were obtained from NCSU. All information in the files had been entered by graduate students at the university as part of a separate NCDOT local calibration research project.
  • Many of the values used are MEPDG defaults; however were applicable project specific traffic and material data has been included.
  • Very little dynamic modulus (E *) data and no subgrade moduli (MR) data for asphalt projects was available.
  • Material data is essentially non-existent for the NCDOT concrete pavement projects. This data was either filed in such a way as to be impossible to find or destroyed due to age. Therefore, the concrete design files were assembled with default values for nearly all inputs.
  • AADTT counts for all projects was available; however, default traffic distributions were used on all projects.
  • Soil type for each project was available from the pavement design files; however, all other soils data consisted of default values.
Review of NCDOT Data

Upon review of the NCDOT populated MEPDG calibration database, the APTech project team identified the following:

  1. The MEPDG calibration database was mainly populated with data to conduct calibration at Level 2 for asphalt and JPC pavements. This is a policy decision taken by NCDOT. Other SHAs may formulate similar decisions based on the common pavement types. It may be difficult for a SHA to obtain Level 1 project specific data prior to construction; however, other similar materials sources may be used by a SHA to obtain the data needed for Level 1 calibration.
  2. The MEPDG calibration database lacks data required for the calibration of CRCP and composite pavements (asphalt over JPCP or CRCP). Both of these pavement types are commonly in the United States (and abroad).
  3. The MEPDG calibration database contains information on new and rehabilitated asphalt pavements and only newly constructed JPCP (i.e., no JPCP rehabilitation projects).
  4. The MEPDG calibration database contains traffic data that includes AADT, truck count, and twenty year traffic projection. NCDOT is in the process of assembling MEPDG traffic data on newly constructed projects as part of a separate study.
  5. As noted previously, the NCDOT collected pavement performance data (i.e., pavement distresses) is not in accordance with the LTPP Distress Identification Manual(FHWA 2003).
MEPDG Calibration Database

The following describes the data contained in the MEPDG calibration database. Though this data is specific to the data definitions contained within the NCDOT pavement management system, it is believed to be applicable to other SHAs since it illustrates the level and amount of data needed for calibration of the MEPDG performance models.

Table 36 describes the data contained in the project reference information table. This table is replicated in all other database tables to ensure that a consistent referencing process is maintained for all data elements.

Table 36. Project reference information.
Label Description
PRJCT_ID Unique number that identifies each project
SCTN_ID Unique number that identifies the section within each project
Latitude Latitude (degree, minute) of the mid-point of each project
Longitude Longitude (degree, minute) of the mid-point of each project
Elevation Elevation (ft) of the mid-point of each project
H20_Tbl_Dpth Depth to water table (ft)
Stationing_Type Describes the units of measure used for stationing (ft)
Stationing_Start Stationing of the project begin location (ft)
Stationing_End Stationing of the project end location (ft)
Design_Life Original pavement design life (years)
Construct_Date Date of original pavement construction
Overlay_Date Date of HMA overlay placement (where applicable)
Traffic_Date Date roadway was opened to traffic
Pavement Type Type of pavement (asphalt, JPCP, or CRCP)

Based on discussion with NCDOT, it was determined that the climatic data contained within the MEPDG would be sufficient for use in the MEPDG calibration process. Therefore, the climatic data for North Carolina that is contained within the MEPDG *.hcd files was not repeated in the MEPDG calibration database. However, if a SHA was interested in adding additional climatic data, the needed data elements are described in table 37.

Table 37. Climatic input descriptions.
Label Description
Year Year climate data was recorded
Month Month climate data was recorded
Day Day climate data was recorded
Hour Hour climate data was recorded
Temperature Mean hourly temperature (°F)
Wind_Speed Mean hourly wind speed (mph)
Percent_Sun Mean hourly percent sunshine
Precipitation Mean hourly precipitation (in)
Relative_Humidity Mean hourly relative humidity

Table 38 includes a description of each AC material data element. Table 38. AC materials input descriptions.

Table 38. AC materials input descriptions.
Name Description
LYR_NBR Layer number
Effctv_Bndr_Cntnt Effective binder content (by weight)
Poisson_Ratio Poisson’s ratio
Existing_Layer Existing layer as opposed to a new layer
Layer_Thickness Layer thickness (in)
Air_Voids Percent air voids
Thermal_Cndctvy Thermal conductivity. (BTU/hr-ft-°F)
Ref_Temp Reference temperature (°F)
Unit_Weight Total unit weight (pcf)
Heat_Capacity Heat capacity (BTU/lb-°F)
E* Dynamic modulus of asphalt mixture (Level 1)
Temperature Temperature (°F)
E*_0_1 Dynamic modulus (psi) at 0.1 Hz
E*_1 Dynamic modulus (psi) at 1 Hz
E*_10 Dynamic modulus (psi) at 10 Hz
E*_25 Dynamic modulus (psi) at 25 Hz
RTFO_SP Superpave binder test data (Level 1 and Level 2)
Temperature Temperature (°F)
G* Binder dynamic modulus (Pa)
Delta Phase angle
RTFO_Conv Conventional binder properties (Level 1 and Level 2)
Temp Temperature (°F)
Softening_Pnt Softening point (P)
Abslt_Vscsty Absolute viscosity (P)
Knmtc_Vscsty Kinematic viscosity (CS)
Spcfc_Grvty Specific gravity
Penetration Penetration
Brkfld_Vscsty Brookfield viscosity
Gradation Gradation properties of asphalt mixture (Level 2 and Level 3)
Retained_3/4 Cumulative percent retained on the ¾ in sieve.
Retained_3/8 Cumulative percent retained on the Ǫ in sieve.
Retained_ No_4 Cumulative percent retained on the #4 sieve.
Passing_No_200 Percent passing the No sieve.
Creep Creep compliance properties (thermal cracking).
Load_Time Loading time (sec).
Creep_-4F Low temperature (-4 °F).
Creep_-14F Mid temperature (14 °F).
Creep_-32F High temperature (32 °F).
Binder Asphalt binder properties (Level 3).
Binder_Type Binder Type
Binder_Grad Binder grade
Therm Crk Thermal cracking properties
Tnsl_Strngth Average tensile strength at 14 °F (psi)
VMA Mixture voids in mineral aggregate (%)
Aggrgt_CTC Aggregate coefficient of thermal contraction (in/in/°F)
Mix_CTC Mix coefficient of thermal contraction (in/in/°F)

Table 39 includes descriptions of each PCC material data element. For much of the PCC materials inputs, NCDOT has limited data. As a result, much of the PCC material (JPCP, NCDOT did not provide any CRCP projects) inputs used the default values provide within the MEPDG.

Table 39. PCC materials input descriptions.
Name Description
LYR_NBR Layer number
Layer_Thickness Layer thickness (in)
CTE Coefficient of thermal expansion (per °F x 10 -6)
Existing_Layer Existing layer as opposed to a new layer
Unit_Weight Unit weight (pcf)
Therm_Conduct Thermal conductivity (BTU/hr-ft-°F)
Poisson_Ratio Poisson’s ratio
Heat_Capacity Heat capacity (BTU/lb-°F)
Design Concrete pavement design features
Curl/Warp_Effective_ Temperature_Difference Permanent curl/warp effective temperature difference (°F)
Joint_Spacing Joint spacing (ft)
Sealant_Type Joint sealant type
Dowel_Diameter Dowel bar diameter (in)
Dowel_Spacing Dowel bar spacing (in)
Tied_PCC Identifies the presence of a tied concrete shoulder
Tied_LTE Load transfer efficiency of the tied concrete shoulder
Widened_Slab Identifies the presence of a widened lane
Slab_Width Width of the widened slab (ft)
PCC-Base_Interface Level of friction between the base and PCC
Base_Erodobility_Index Base erodobility index
Loss_of_Friction Loss of full friction (age in months)
Steel_Reinforcement Percent steel (%)
Reinforcement_Steel_Diameter Bar diameter (in)
Depth_of_Reinforcement Steel depth (in)
Base/Slab_Friction_Coefficient Base/slab friction coefficient
Crack_Spacing Mean crack spacing (in)
Mix Mix design properties
Cmnt_Typ Cement type
Cmntitious_Cntnt Cementitious content
W/C_Ratio Water-cement ratio
Ultimate_Shrinkage Ultimate shrinkage
Reverse_Shrink Reverse shrinkage
Curing_Type Curing type
Strength Strength properties
Age Age (yrs)
Elstc_Modulus Elastic modulus (psi)
Modulus_of_Rupture Modulus of rupture (psi)
Comp. Strength Compressive strength (psi)
Splt_Tnsle_Strngth Split tensile strength (psi)

Table 40 includes a description of each PCC maintenance data element. Table 40. PCC maintenance input descriptions.

Table 40. PCC maintenance input descriptions.
Name Description
Slabs_Transverse_Cracking_Before_Restoration Number of transverse cracks prior to restoration
Repaired_Slabs_After_Restoration Number of transverse cracks after restoration
CRCP_Existing_Punchouts Number of existing punchouts
Dynamic_Modulus_Subgrade_Reaction Dynamic modulus of subgrade reaction

Table 41 includes a description of each unstabilized/stabilized material data element.

Table 41. Unstabilized/stabilized materials input descriptions.
Name Description (and measure where applicable)
LYR_NBR Layer number
Layer_Thickness Layer thickness (in)
Layer_Type Layer type (aggregate base, bedrock, soil, or stabilized subgrade)
Last_Layer (semi-infinite) Identifies layer as the last layer of the pavement section
Bedrock Bedrock layer inputs
Type Soil type
Unit_Weight Unit weight (pcf)
Poisson_Ratio Poisson’s ratio
Resilient_Modulus Resilient modulus (psi)
Gradation(for each layer) Gradation inputs for each unstabilized/stabilized layer
Passing_3_5 Mean percent passing 3-½ in screen
Passing_3 Mean percent passing 3 in screen
Passing_2_5 Mean percent passing 2-½ in screen
Passing_2 Mean percent passing 2 in screen
Passing_1_5 Mean percent passing 1-½ in screen
Passing_1 Mean percent passing 1 in screen
Passing_3/4 Mean percent passing ¾ in screen
Passing_1/2 Mean percent passing ½ in screen
Passing_3/8 Mean percent passing Ǫ in screen
Passing_#4 Mean percent passing #4 screen
Passing_#8 Mean percent passing #8 screen
Passing_#10 Mean percent passing #10 screen
Passing_#16 Mean percent passing #16 screen
Passing_#20 Mean percent passing #20 screen
Passing_#30 Mean percent passing #30 screen
Passing_#40 Mean percent passing #40 screen
Passing_#50 Mean percent passing #50 screen
Passing_#60 Mean percent passing #60 screen
Passing_#80 Mean percent passing #80 screen
Passing_#100 Mean percent passing #100 screen
Passing_#200 Mean percent passing #200 screen
Passing_0_02mm Mean percent passing 0.020 mm screen
Passing_0_002mm Mean percent passing 0.002 mm screen
Passing_0_001mm Mean percent passing 0.001 mm screen
PI Plasticity index
LL Liquid limit
Compacted_Layer Compacted layer
Stabilized Inputs for stabilized layer
Unit_Wght Unit weight (pcf
Poisson_Ratio Poisson’s ratio
Elastic/Resilient_Mod Elastic/resilient modulus (psi)
Minimum_Mod Minimum elastic/resilient modulus (psi)
Mod_of_Rupture Modulus of rupture (psi)
Therm_Cndctvty Thermal conductivity (BTU/hr-ft-°F)
Heat_Capacity Heat capacity (BTU/lb-°F)
Strength (for each layer) Strength inputs for each unstabilized/stabilized layer
k1 Regression constants (used for Level 1 calculation of MR)
k2 Regression constants (used for Level 1 calculation of MR)
k3 Regression constants (used for Level 1 calculation of MR)
Poisson_Ratio Poisson’s ratio
Ltrl_Pressure Lateral pressure
Modulus Resilient modulus (psi)
CBR California Bearing Ratio
R_Val R-Value
Lyr_Coefnt AASHTO layer coefficient
DCP Dynamic Cone Penetrometer (mm/blow)

Table 42 includes a description of the pavement performance data elements for HMA pavements and table 43 includes the PCC pavement performance data elements.

Table 42. Pavement performance input descriptions – HMA.
Name Description
HMA Analysis Analysis parameters for flexible pavement
IRI_Limit Terminal IRI limit (in/mi)
IRI_Reliability Terminal IRI reliability (%)
Surface_Down_Limit Surface down longitudinal cracking limit (ft/mi)
Surface_Down_Reliability Surface down longitudinal cracking reliability (%)
Bottom_Up_Limit Bottom up alligator cracking limit (%)
Bottom_Up_Reliability Bottom up alligator cracking reliability (%)
Thermal_Fracutre_Limit Thermal fracture limit (ft/mi)
Thermal_Fracture_Reliability Thermal fracture reliability (%)
Stabilized_Fatigue_Limit Chemically stabilized layer fatigue fracture limit (%)
Stabilized_Fatigue_Reliability Chemically stabilized layer fatigue fracture reliability (%)
Total_Deformation_Limit Permanent deformation – total pavement limit (in)
Total_Deformation_Reliability Permanent deformation – total pavement reliability (%)
AC_Deformation_Limit Permanent deformation – AC only limit (in)
AC_Deformation_Reliability Permanent deformation – AC only reliability (%)
Table 43. Pavement performance input descriptions – PCC.
Name Description
PCC Analysis Analysis parameters for rigid pavements
IRI_Limit Terminal IRI limit (in/mi)
IRI_Reliability Terminal IRI reliability (%)
Transverse_Crack_Limit Transverse cracking limit (% slabs cracked)
Transverse_Crack_Reliability Transverse cracking reliability (%)
Joint_Fault_Limit Mean joint faulting limit (in)
Joint_Fault_Reliability Mean joint faulting reliability (%)
Punchouts_Limit CRCP existing punchout limit (number of punchouts)
Punchouts_Reliability CRCP existing punchout reliability (%)
Crack_Width_Limit Maximum CRCP crack width (in)
Crack_LTE_Limit Minimum crack load transfer efficiency (%)
Min_Crack_Spacing_Limit Minimum crack spacing (ft)
Max_Crack_Spacing_Limit Maximum crack spacing (ft)
Maintenance Rigid rehabilitation
Transverse_Crack_Before Before restoration, percent of slabs with transverse cracks plus percent of previously repaired/replaced slabs (%)
Transverse_Crack_After After restoration, total percent repaired/replaced slabs (%)
CRCP_Punchouts Number of existing punchouts (per mile)
Subgrade_Dynamic_Modulus Dynamic modulus of subgrade reaction (psi/in)
  Month modulus of subgrade reaction measured

Table 44 includes a description of each traffic data element. NCDOT has recommended the use the MEPDG default values for the monthly adjustments factors; therefore, this information is not shown in table 44.

Table 44. Traffic input descriptions.
Name Description
AADTT Initial two-way average annual daily truck traffic
Direction Direction of traffic
No_Design_Lane Number of lanes in the design direction
%_Trcks_Dsgn_Dir Percent of trucks in the design direction (%)
%_Trcks_Dsgn_Lane Percent of trucks in design lane (%)
Speed Operational speed (mph)
Growth_Rate Traffic growth rate (%)
General Traffic Inputs
Wheel_Location Mean wheel location (inches from the lane marking)
Trffc_Wander_Stdev Traffic wander standard deviation (in)
Design_Lane_Width Design lane width (ft)
Axle Configuration
Avg_Axle_Width Average axle width (edge-to-edge), outside dimension (ft)
Dual_Tire_Spacing Dual tire spacing (in)
Tire_Pressure Tire pressure (psi)
Axle_Spcing_Tandem Tandem axle spacing (in)
Axle_Spcing_Tridem Tridem axle spacing (in)
Name Description
Axle_Spcing_Quad Quad axle spacing (in)
Wheelbase
Wheelbase_Short Average short axle spacing (ft)
% Trucks_Short Percent of trucks – short axle spacing (%)
Wheelbase_Medium Average medium axle spacing (ft)
% Trucks_Medium Percent of trucks – medium axle spacing (%)
Wheelbase_Long Average long axle spacing (ft)
% Trucks_Long Percent of trucks – long axle spacing (%)
Axle/Truck Number of axles/truck
Class FHWA truck class 4 – 13
Single Average number of single axles per truck class
Tandem Average number of tandem axles per truck class
Tridem Average number of tridem axles per truck class
Quad Average number of quad axles per truck class
Traffic Volume Adjustment Factors
Hour Distrib Hourly distribution
Midnight – 11:00 PM Hourly truck traffic distribution by hour (%)
Total Sum of hourly distribution (must total 100%)
Monthly Adjust Monthly adjustments
Month Month of the year (January – December)
Class_1 – Class_13 Monthly adjustment factor for each FHWA truck class 1 – 13
Vehicle Distrib Vehicle class distribution
Class_1 – Class_13 AADTT distribution by vehicle class (%)
Total Sum of AADTT distribution (must total 100%)
Axle Load Distribution Factors
Single Single axle
Month Month of the year (January – December)
Class FHWA truck class 1 – 13
Total Sum of axle load distribution factors (must total 100%)
3000 – 41000 Percent of axles in each load interval (1000 lb increments)
Tandem Tandem axle
Month Month of the year (January – December)
Class FHWA truck class 1 – 13
Total Sum of axle load distribution factors (must total 100%)
6000 – 82000 Percent of axles in each load interval (2000 lb increments)
Tridem Tridem axle
Month Month of the year (January – December)
Class FHWA truck class 1 – 13
Total Sum of axle load distribution factors (must total 100%)
12000 – 102000 Percent of axles in each load interval (3000 lb increments)
Quad Quad axle
Month Month of the year (January – December)
Class FHWA truck class 1 – 13
Total Sum of axle load distribution factors (must total 100%)
12000 – 102000 Percent of axles in each load interval (3000 lb increments)

Table 45 through table 47 includes a description of each agency data element (HMA, JCP, and CRC, respectively).

Table 45. Agency data input descriptions – HMA.
Name Description (and measure where applicable)
CNTY_NBR NCDOT county number – value ranges from 1-100 and is based on the alphabetical order of counties
RTE_NBR NCDOT eight digit route number
DIR Direction
BGN_MLPST_NBR Begin milepost number
BGN_DES Begin description
SCTN_LEN Length of the survey section
END_MLPST_NBR End milepost number
END_DES End description
SRVY_YR_NBR Survey year number (condition data year)
ALGTR_NONE_PCT Percent of route with no alligator cracking – stored number is percent/10
ALGTR_LOW_PCT Percent of route with no low severity alligator cracking – stored number is percent/10 Measure– Hairline cracks about ⅛" wide
ALGTR_MDRT_PCT Percent of route with moderate severity alligator cracking – stored number is percent/10 Measure– May be slightly spalled, about ¼" wide
ALGTR_HGH_PCT Percent of route with no high severity alligator cracking – stored number is percent/10 Measure– Pieces appear loose, severely spalled, about ⅜" to ½" wide
TRNSVRS_CD Transverse cracking distress level – (N)one, (L)ight, (M)oderate, (S)evere Measure– L = ¼" wide, no spalling; M = may be spalled, ¼ to ½" wide, 5 to 20 ft apart; S = may be severely spalled, > ½" wide, 1 to 2 ft apart
RUT_CD Rutting distress level – (N)one, (L)ight, (M)oderate, (S)evere Measure– L = ¼" to < ½" deep; M = ½" to < 1" deep; S = > 1" deep
RVL_CD Raveling distress level – (N)one, (L)ight, (M)oderate, (S)evere Measure– L = small amounts of stripping, aggregate starting to wear away; M = some stripping is evident and in small areas or aggregate broken away; S = stripping very evident, aggregate accumulation
OXDTN_CD Transverse cracking level – (N)one, (S)evere Measure– N = not present; S = present
BLD_CD Bleeding distress level – (N)one, (L)ight, (M)oderate, (S)evere Measure– L = present on 10 to 25% of section; M = present on 26 to 50% of section; S = present on > 50% of section
PTCH_CD Patching distress level – (N)one, (L)ight, (M)oderate, (S)evere Measure– L = present on 6 to 15% of section; M = present on 16 to 30% of section; S = present on greater than 30% of section
Name Description (and measure where applicable)
RIDE_CD Ride distress level – (N)one, (L)ight, (M)oderate, (S)evere Measure– L = minimum tire noise, isolated bumps/dips (up to ¼ of the section); M = ¼ to ½ of section is uneven with bumps/dips/ruts; S = more than ½ section is uneven and bumpy
ADT_NBR Average daily traffic for the section
FAS_CD Federal aid status (largely a deprecated field)
RTG_NBR NCDOT composite rating number – calculated from the above distress fields
SYS_CD Route type
RSRFC_YR_NBR Last known resurface year (not used for interstates)
RSRF_THCKNS_NBR Last known resurface thickness (not used for interstates)
SBDVSN_RRL_CD Subdivision or rural route CD
SCTN_CST_AMT Estimate treatment cost to repair section based on current distresses
LANE_MILE_CST_AMT Estimated treatment cost per lane mile to repair section based on current distresses
PVMT_TYP_CD Pavement type code Measure– P = plant mix, B = bituminous surface treatment, S = slurry seal
PVMT_WID Pavement width
LANE_NBR Number of lanes
SHLDR_CD Shoulder type Measure– P = plant mix, B = bituminous surface treatment, S = slurry seal, U = unpaved
SHLDR_WID Shoulder width
CURB_GTR_CD Curb and gutter indicator Measure– Y = on both sides; N = on one side only
MIN_IRI_NBR Minimum IRI number in the section
MAX_IRI_NBR Maximum IRI number in the section
AVG_IRI_NBR Average IRI number in the section
IRI_YR_NBR Year IRI data was collected
Table 46. Agency data input descriptions – JCP.
Name Description (and measure where applicable)
CNTY_NBR NCDOT county number – value ranges from 1-100 and is based on the alphabetical order of counties
RTE_NBR 5 digit route number
DIR Cardinal direction
BGN_MLPST_NBR Begin milepost number
END_MLPST_NBR End milepost number
SRVY_YR_NBR Survey year number (condition data year)
BGN_DES Begin description
END_DES End description
LANE_NBR Number of lanes
CURB_GTR_CD Curb and gutter indicator Measure– Y = on both sides; N = on one side only
JNT_SPCG_NBR Joint spacing (ft)
SLAB_NBR Number of slabs surveyed
PVD_SHLDR_CD Paved shoulder type MeasureP = plant mix, B = bituminous surface treatment, S = slurry seal
PVD_SHLDR_WID Paved shoulder width
PVD_SHLDR_CNDTN_CD Paved shoulder condition Code (N, L, M, S) Measure– Asphalt: L = good condition; M = acceptable condition, some cracking ¼" to ½" wide; S = unacceptable condition, cracking > ¼" wide, edge breaking away Concrete: L = good condition; M = Cracks < ⅛" wide, light to moderate spalling; S = cracks over ⅛" wide, unstable material, faulting > ¼"
UNPVD_SHLDR_WID Unpaved shoulder width (ft)
SRFC_WEAR_NONE_PCT Percent of pavement with no detectable surface wear
SRFC_WEAR_LGHT_PCT Percent of pavement with low levels of detectable surface wear Measure– Texture worn away with < 25% visible aggregate, small popouts may be visible
SRFC_WEAR_MDRT_PCT Percent of pavement with moderate levels of detectable surface wear Measure– Texture worn away with 25 to 50% visible aggregate, small extensive popouts may be present
SRFC_WEAR_SVR_PCT Percent of pavement with high levels of detectable surface wear Measure– Texture worn away with > 50% visible aggregate, large extensive popouts may be present
PMPG_NBR Number of joints exhibiting pumping
LNGTDNL_LGHT_NBR Number of slabs with low severity longitudinal cracking Measure– Crack widths < ⅛", no spalling or faulting
LNGTDNL_MDRT_NBR Number of slabs with moderate severity longitudinal cracking Measure– Crack widths ⅛" to ½", spalling less than 3", or faulting up to ½", may be sealed
LNGTDNL_SVR_NBR Number of slabs with high severity longitudinal cracking Measure– Crack widths > ½", spalling greater than 3", or faulting greater than ½"
CRNR_LGHT_NBR Number of slabs with low severity corner breaks Measure– Cracks well sealed or hairline, no faulting, spalling or break-up
CRNR_MDRT_NBR Number of slabs with moderate severity corner breaks Measure– Low to medium severity spalling, faulting < ½", no pieces broken
CRNR_SVR_NBR Number of slabs with high severity corner breaks Measure– Moderate to severe spalling, faulting > ½", broken into two or more pieces
SPLL_LGHT_NBR Number of slabs with low severity spalls Measure– Spalls < 3" wide
SPLL_MDRT_NBR Number of slabs with moderate severity spalls Measure– Spalls 3" to 6" wide
SPLL_SVR_NBR Number of slabs with high severity spalls Measure– Spalls > 6" wide
TRNSVRS_LGHT_NBR Number of slabs with low severity transverse cracking Measure– Crack widths < ⅛", no spalling or faulting
TRNSVRS_MDRT_NBR Number of slabs with moderate severity transverse cracking Measure– Crack widths ⅛" to ½", spalling less than 3", or faulting up to ½", may be sealed
TRNSVRS_SVR_NBR Number of slabs with high severity transverse cracking Measure– Crack widths > ½", spalling greater than 3", or faulting greater than ½"
SEAL_LGHT_NBR Number of seals exhibiting light deterioration Measure– Exists on < 10% of joint
SEAL_MDRT_NBR Number of seals exhibiting moderate deterioration Measure– Exists on 10 to 50% of joint
SEAL_SVR_NBR Number of seals exhibiting severe deterioration Measure– Exists on > 50% of joint
FALT_NBR Average faulting in the survey section
ADT_NBR Average daily traffic for the section
RTG_NBR NCDOT composite rating number – calculated from the above distress fields
RIDE_CD Ride distress level – (N)one, (L)ight, (M)oderate, (S)evere Measure– L = few bumps and dips, joints are fairly smooth; M = some joints appear faulted, joints or cracks cause bumps and unevenness; S = most joints severely faulted, cracks cause unevenness and surface may be broken, cracked or worn away
MIN_IRI_NBR Minimum IRI number in the section
MAX_IRI_NBR Maximum IRI number in the section
AVG_IRI_NBR Average IRI number in the section
IRI_YR_NBR Year IRI data was collected
Table 47. Agency data input descriptions – CRC.
Name Description
SRVY_YR_NBR Survey year number (condition data year)
CNTY_NBR NCDOT county number. Value ranges from 1-100 and is based on the alphabetical order of counties
RTE_NBR 5 digit route number
DIR Cardinal direction
BGN_MLPST_NBR Begin milepost number
BGN_DES Begin description
END_MLPST_NBR End milepost number
END_DES End description
LANE_NBR Number of lanes
CURB_GTR_CD Curb and gutter indicator
PVD_SHLDR_CD Paved shoulder type Measure– P = plant mix, B = bituminous surface treatment, S = slurry seal.
PVD_SHLDR_WID Paved shoulder width
PVD_SHLDR_CNDTN_CD Paved shoulder condition code (N, L, M, S)
UNPVD_SHLDR_WID Unpaved shoulder width
UNPVD_SHLDR_CNDTN_CD Unpaved shoulder condition code (N, L, M, S)
SHLDR_DRPOFF_CD Shoulder drop-off severity (N, L, M, S)
SHLDR_LANE_JNT_CD Shoulder and travel lane joint condition (N, L, M, S)
CNCRT_PTCH_GOOD_NBR Number of good quality concrete patches in the survey section
CNCRT_PTCH_FAIR_NBR Number of fair quality concrete patches in the survey section
CNCRT_PTCH_POOR_NBR Number of poor quality concrete patches in the survey section
ASPHLT_PTCH_NBR Number of asphalt patches
SRFC_WEAR_NONE_PCT Percent of pavement with no detectable surface wear
SRFC_WEAR_LGHT_PCT Percent of pavement with low levels of detectable surface wear
SRFC_WEAR_MDRT_PCT Percent of pavement with moderate levels of detectable surface wear
SRFC_WEAR_SVR_PCT Percent of pavement with high levels of detectable surface wear
PMPG_NBR Number of joints exhibiting pumping
RIDE_GOOD_PCT Percent of pavement with good ride quality
RIDE_FAIR_PCT Percent of pavement with fair ride quality
RIDE_POOR_PCT Percent of pavement with poor ride quality
LNGTDNL_LGHT_LEN Total length of low severity longitudinal cracking in the survey section
LNGTDNL_MDRT_LEN Total length of moderate severity longitudinal cracking in the survey section
LNGTDNL_SVR_LEN Total length of high severity longitudinal cracking in the survey section
TRNSVRS_MDRT_NBR Number of moderate severity transverse cracks
TRNSVRS_SVR_NBR Number of high severity transverse cracks
PNCH_LGHT_NBR Number of low severity punch-outs
PNCH_MDRT_NBR Number of moderate severity punch-outs
PNCH_SVR_NBR Number of high severity punch-outs
NRW_CRCK_NBR Total length of narrow cracks in the survey section
Y_CRCK_NBR Total length of y-cracks in the survey section
ADT_NBR Average daily traffic for the section
RTG_NBR Not calculated for CRC pavements
MIN_IRI_NBR Minimum IRI number in the section
MAX_IRI_NBR Maximum IRI number in the section
AVG_IRI_NBR Average IRI number in the section
IRI_YR_NBR Year IRI data was collected

Summary

The development of a MEPDG calibration database is essential for the calibration and validation of the MEPDG performance models using pavement management data. This is necessary not only for the initial calibration/validation process, but will be critical for future updates and modifications.

A preliminary MEPDG calibration database was provided to NCDOT by the APTech research team that contained all of the data elements identified in the preliminary framework. The NCDOT pavement management group reviewed the preliminary MEPDG calibration database and determined that a number of changes (e.g., storage of input values, addition of NCDOT specific data, database structure) would be necessary to adequately address the various data collection/storage needs of the NCDOT. Based on discussion with the APTech research team, it was determined that it would be more efficient for the NCDOT pavement management group to modify the MEPDG calibration database to meet the data and formatting needs of the NCDOT.

This chapter has documented the verification of input and pavement performance data for NCDOT pavement sections to be used in the MEPDG calibration process. A total of thirty-one projects, consisting of nineteen new asphalt pavement sections, three thin asphalt pavement sections, three asphalt overlay sections, and six new JPCP sections, have been entered into the MEPDG calibration database. In addition, NCDOT has populated the MEPDG calibration database with all available project, materials, construction, and traffic data. NCDOT has also determined that the climatic files contained within the MEPDG are sufficient for the calibration process.

The APTech team has reviewed the MEPDG calibration database and found that it meets the framework for this project.

More Information

Contact

Nastaran Saadatmand
Office of Asset Management, Pavements, and Construction
202-366-1337
E-mail Nastaran

 
 
Updated: 10/12/2011
 

FHWA
United States Department of Transportation - Federal Highway Administration