In late June 1969, the Kentucky Department of Highways contracted to have experimental, longitudinal centerline grooves, 15 feet long at 80-foot intervals, cut into both sets of dual lanes of a 2.7-mile portion of I 71 in Carroll County. When the centerline was painted in an otherwise normal way, the skip lines were alternately on grooved and ungrooved surfaces. The roadway was opened to traffic on July 15, 1969. An interim performance report contained detailed information on the test site, grooving procedures, groove configuration, initial striping efforts, and preliminary evaluations of the relative effectiveness of the grooved stripe. The purposes of this report are: 1) to update the observations cited in the interim report, 2) to evaluate the grooved centerlines during rainy, nighttime conditions, and 3) to record wear and durability histories of grooved and ungrooved lines.

Report Date


Report Number

No. 314

Digital Object Identifier