Delaware starts construction on states first Diverging Diamond Interchange

Dover, Del. — Delaware Governor Jack Markell and Transportation Secretary Jennifer Cohan, joined by local officials and invited guests, assembled recently near the site of the State Route (SR) 1 and Route 72 junction in celebration of the groundbreaking for the creation of Delaware's first Diverging Diamond Interchange (DDI). Currently in operation or design in 48 of 50 states, Delaware's $7 million dollar design-build project is being constructed by Diamond Materials of Wilmington and JMT Construction of Newark.

"When I became Secretary of Transportation a little more than a year ago, I made a commitment to innovation, and the Diverging Diamond Interchange is one of the most innovative concepts in road design," said DelDOT Secretary Jennifer Cohan. "Only 64 Diverging Diamond Interchanges have been constructed in the United States, and the one at Route 72 and SR 1 will be the first one in Delaware. The Diverging Diamond here will enable vehicles to enter and exit SR 1 without having to cross lanes of oncoming traffic, improving safety and decreasing congestion and it will cost a lot less than more traditional interchange arrangements. That is the sort of innovation we will continue to pursue at DelDOT."

Listed by Popular Science magazine as a top traffic engineering innovation, the Diverging Diamond Interchange 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 longer vehicles 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.

"Implementing the Diverging Diamond concept on our network of roads and bridges represents the efficient and effective approach to transportation investments that our citizens deserve," Governor Markell said. "We will improve safety, while using an interchange design that can be installed at a quarter of the cost of other methods. This is exactly the type of project we wanted to see when we worked with the General Assembly to approve a $400 million increase in transportation funding over the next six years."

"High-quality roads, highways and bridges keep our economy on the move and we know that investments like this are investments in the success of our entire region," said United States Senator Tom Carper. "The diverging diamond project will not only ease congestion along a major thoroughfare in New Castle County, but it will also implement innovative traffic engineering that will make people safer as they travel through the First State."

"The new Diverging Diamond Interchange at SR 1 and Route 72 shows the power of collaboration between federal and state partners," said United States Congressman John Carney. "This innovative design will make it easier and safer for folks to cross this busy intersection. I applaud the Federal Highway Administration and DelDOT for bringing this idea to Delaware, and I look forward to seeing its completion."

The Federal Highway Administration (FHWA) has 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.

For further information visit the project website at https://sr1.deldot.gov/