Chip Seal Treatment

Surface treatments such as chip seals originated in the 1920s.  These early uses were predominantly as wearing courses in the construction of low-volume gravel roads. In the past 75 years, chip seals have evolved into maintenance treatments that can be successful on both low-volume and high-volume pavements.  The popularity of chip seals is a direct result of their low initial costs in comparison with those of thin asphalt overlays and other factors influencing treatment selection where the structural capacity of the existing pavement is sufficient to sustain its existing loads.

Reference: NCHRP Synthesis 342.  http://www.trb.org/Publications/Blurbs/155807.aspx