LTPP Logo Long Term Pavement Performance Logo

LTPP TSSC Home

Data User's Corner





LTPP TABLE NAVIGATOR: Field View


Fields for table: BAKCAL_LAYER_LINK

Field NameCodesData TypeUnitsTest ProtocolDescription
STATE_CODE
STATE_PROVINCENUMBER(2)


Numerical code for state or province. U.S. codes are consistent with Federal Information Processing Standards.
SHRP_ID

VARCHAR2(4)


Test section identification number assigned by LTPP program. Must be combined with STATE_CODE to be unique.
CONSTRUCTION_NO

NUMBER(2)


Event number used to relate changes in pavement structure with other time dependent data elements. This field is set to 1 when a test section is initially accepted into LTPP and is incremented with each change to the layer structure.
LAYER_NO

NUMBER(2)


Unique sequential number assigned to pavement layers, starting with layer 1 as the deepest layer (subgrade).
BC_STRUCTURE_NO

NUMBER(2)


Number identifying the structure used for backcalculation purposes.
BC_LAYER_NO

NUMBER(2)


Backcalculation layer number. Layer 1 is the surface layer.
BEST_FIT_LAYER

VARCHAR2(4)


Indicates whether the field was part of the base or PCC layer in the best fit process.
SIGNIFICANT_STRUCTURE_CHANGE

VARCHAR2(2)


Flag field identifying whether the structure available to the backcalculation team was significantly different than the current structure - not layer specific.