The City of Frisco tasked KSA with designing pavement replacement along sections of Big Horn Trail and Custer Trail in the Custer Farms estate subdivision, as well as repaving the entrance at the intersection of Big Horn Trail and Custer Road.  The subdivision is somewhat unique as it was platted in the late 70’s and all of the existing streets in the subdivision are only 18 feet wide and are curbless.  All the existing pavement in the subdivision (other than a small, recently replaced section) consists of deteriorated concrete pavement that varies in thickness from 3-6” and was poured directly over expansive native soils, without any subgrade preparation.
KSA designed approximately 2,800 square yards of new 8” thick concrete pavement placed over 6” of flexbase.  The challenging part of the project was phasing the construction to maintain access to the property owners while accommodating construction of a very narrow road section.  In order to maintain adequate ingress/egress for the property owners KSA designed a very detailed construction phasing plan, utilizing high early strength concrete in several areas to facilitate opening of the new pavement to traffic in a much shorter time frame.  The new pavement was designed to maintain the existing drainage patterns, and followed the vertical alignment of the existing roads.  To allow the much thicker pavement section several culverts had to be replaced at lower elevations, and grading of the existing drainage areas was improved to accommodate the lowered culverts.  At the request of City staff KSA also designed replacement water service leads to replace all the small diameter water services that crossed under the new pavement to minimize future maintenance issues.