This interchange reconfiguration was necessary to address growth in the surrounding communities and needed improvements to McCoy Road and Wilson Boulevard, which connects SR 72 and McCoy Road.  The Department opted to use a design-build delivery method in order reduce the time from project inception to completion. 

A Diverging Diamond Interchange (DDI) – the first of its kind in Delaware – was chosen as a retrofit to reconfigure the existing SR 1/SR 72 traditional  diamond interchange. Listed by Popular Science magazine as a top traffic engineering innovation, the Diverging Diamond Interchange (DDI) is unusual in that it requires traffic on a freeway overpass to briefly drive on the opposite side of the road to make uninterrupted left turns.  This innovative interchange, which was completed more than one month ahead of schedule, allows vehicles to enter and exit SR 1 without a dedicated left turn signal phase for oncoming traffic, thereby increasing operational efficiency and improving safety.

Diamond Materials was awarded the $7.1M project in December 2015, and soon thereafter hired JMT as the design engineer to work alongside Diamond Materials throughout the project. 

The new DDI at SR 1 and SR 72 opened to traffic in November 2016 before the holiday season and in advance of the scheduled completion date of December 2016.  Since the DDI’s opening, DelDOT noted operations have improved dramatically.