15 March 2001
DISTRESS 48, LONGITUDINAL AND TRANSVERSE CRACKING
(NON-PCC JOINT REFLECTIVE)
10.1. Description. Longitudinal cracks are parallel to the pavement's center-line or laydown
direction. They may be caused by (1) a poorly constructed paving lane joint, (2) shrinkage of the
AC surface due to low temperatures or hardening of the asphalt, or (3) a reflective crack caused
by cracks beneath the surface course, including cracks in PCC slabs (but not at PCC joints).
Transverse cracks extend across the pavement at approximately right angles to the pavement
center line or direction of laydown. They may be caused by items 2 or 3 above. These types of
cracks are not usually load-associated. If the pavement is fragmented along a crack, the crack is said
to be spalled. Deduct curves for longitudinal and transverse cracking are shown in Figure 10.1.
10.2. Severity Levels.
10.2.1. L. Cracks have either minor spalling (little or no FOD potential) or no spalling. The
cracks can be filled or nonfilled. Nonfilled cracks have a mean width of 1/4 inch (6.4 millimeters)
or less; filled cracks are of any width, but their filler material is in satisfactory condition
(Figures 10.2. and 10.3.).
10.2.2. M. One of the following conditions exists: (1) cracks are moderately spalled (some FOD
potential) and can be either filled or nonfilled of any width; (2) filled cracks are not spalled or are
only lightly spalled, but the filler is in unsatisfactory condition; (3) nonfilled cracks are not spalled
or are only lightly spalled, but mean crack width is greater than 1/4 inch (6.4 millimeters); or
(4) lightly random cracking exists near the crack or at the corners of intersecting cracks
(Figures 10.4. and 10.5.).