The B table has the representative values for each section. After being loaded into the database and before data are released to the public, a series of QC checks are performed to ensure the integrity of the data. Mandatory checks review fields that must have data for the database software to function. Logic checks are used to ensure data compatibility across tables, e.g., asphalt testing being done on asphalt layers. Range checks are used to compare data against allowable minimums, maximums, or specific values.
Verification is used to ensure that sections exist for which data have been collected.
Each data record must successfully complete the checks to be released for public use. QC checks performed on the database are shown in the LTPP IMS Data Quality Checks Manual , which can be downloaded from this site in the Resource Documents section of the Library. General guidelines for traffic data are provided in LTPP Traffic Directive 10, Revised Data Collection Plan for LTPP Sites , and Traffic Directive 11, Protocol for Calibrating Traffic Data Collection Equipment . The extent to which individual agencies have met these guidelines has varied. The traffic tables store annual traffic summary statistics.