In July 1986, the Arizona Transportation Research Center (ATRC) coordinated the installation of a joint sealant test site near Flagstaff, between mile posts 331.5 and 332.2, on the southbound lanes of Interstate 17. The original project was constructed in 1974, with 8 in. (20 cm) of portland cement concrete pavement (PCCP) over 6 in. (15 cm) of cement treated base (CTB). The test site consisted of 200 transverse joints sawed 2 in. (5 cm) deep, skewed 1:6, and spaced at a repeating sequence of 17, 15, 13, and 15 ft (5.2, 4.6, 4.0, and 4.6 m). The objective of the project was to evaluate the performance of five joint sealants: Dow Corning 888, Superseal 888, Allied Koch 9005, Crafco Roadsaver 231, and W.R. Meadows Sof-Seal. The highway sections abutting this test site were also rehabilitated and their pavement joints were sealed with Superseal 444 which, at that time, was a specified sealant in the Arizona Department of Transportation (ADOT) standards. Field evaluations of the joint sealants were performed at nine months, one year, 1.5 years, 3 years, and 8 years after construction. The evaluations were based on: (i) sealant flexibility, (ii) length of joint with missing sealant, (iii) adhesive and cohesive failure of sealant, (iv) joint width and sealant depth, (v) joint spalling, (vi) sealant recess, (vii) Falling Weight Deflectometer testing, and (viii) slab faulting. Generally, it appeared that after about eight years of service all five sealants had exhibited comparable performance level. Clearly, all test sealants performed better than Superseal 444 which was an ADOT specified joint sealant when the test site was installed in 1986.