Dover, Del. — The Delaware Department of Transportation (DelDOT) announced that, as part of the State Route 1 Widening Program, members of its design team will be performing some land surveying, field walks and studying of soil conditions within the vicinity of the State Route 1 and Route 72 junction in preparation for the construction of the Diverging Diamond Interchange (DDI) at this intersection.
The following video explains the DDI.
Actual construction of the interchange is expected to commence during the early spring with Diamond Materials of Wilmington and JMT Construction of Newark performing the $7 million design-build project.
Listed by Popular Science magazine as a top traffic engineering innovation, the 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. There is a significant improvement in safety, since no long turns must clear opposing traffic and all movements are discrete, controlled by traffic signals. The design has been successfully applied in other states and is recognized as a cost-effective method of achieving enhanced traffic flow and safety without widening an existing overpass.
The Federal Highway Administration awarded DelDOT an Accelerated Innovation Deployment (AID) Demonstration grant of $1 million which provides funding as an incentive for eligible applicants to accelerate the implementation and adoption of innovation in highway transportation.