PILOT IMPLEMENTATION OF A NEW SYSTEM TO CALCULATE IRI USED FOR PAVEMENT DESIGN PROCEDURES - TECHNICAL REPORT

The pilot implementation of the new system to calculate International Roughness Index (IRI) used for pavement design purposes and applied to the design of pavements on expansive clay subgrades was conducted successfully. Six training sessions were conducted in three Districts: three for design engineers and three for laboratory technicians. Three sets of testing equipment were received, set up, calibrated, and made operational in the three district labs. Two computer programs, one for design and the other for the analysis of a pavement cross-section, to determine the expected performance of expansive clay roughness countermeasures were delivered to the three districts. User guides for each of the programs were provided to each of those in attendance. It is recommended that statewide implementation should now proceed to make this capability available to other districts within the state that have pavement performance problems caused by expansive clay roughness. The statewide implementation effort should include the monitoring validation described above, technical support of the computer programs and laboratory testing, additional training sessions in at least six more districts, and involvement of consulting engineers in the training sessions.