Double Crossover Diamond Interchange
What is a double crossover diamond interchange (DCD)?
Most interstate entrance and exit ramps are built as conventional diamond interchanges. Drivers move on and off the interstate and cycle through varying numbers of traffic signals. When making left turns, they must do so in front of oncoming traffic.
In a double crossover diamond Interchange, or DCD, traffic through an interchange follows clearly-defined curbs, signs, pavement markings and state-of-the-art signals to move briefly over to the left side of the road. This eliminates the need for drivers to turn left in front of oncoming traffic. Drivers who need to continue through the interchange then cross back over to the right side of the road, leading to the “double crossover” name.
Watch a brief video of how to drive through a DCD, I-75 I-71 DCD interchange at Mt.Zion Road (KY 536) in Florence, Kentucky provided by 75crossings.com
What are the benefits of a DCD?
DCDs are proven to dramatically improve safety because they eliminate numerous traffic conflict points.
Additionally, because speeds are reduced within the DCD, if crashes do happen, they are often less severe.
Because there is no need for a separate signal phase to allow for left turns, DCDs also move drivers through high traffic areas much more efficiently. DCDs are quicker and less expensive to build than many other interchange alternatives.
Why do drivers who travel through DCDs say they are simple and easy?
Driving through a DCD is very intuitive. Clear pavement markings, signs, raised medians, curbs and state-of-the-art traffic signals guide drivers all the way through the interchange.
How many DCDs are there in the United States?
Though popular in France since the 1970s, the first U.S. DCD opened in Springfield, Missouri, in 2009. Today, there are 89 DCDs across the country.
Are there other DCDs in Kentucky?
The first and only DCD interchange in Kentucky (pictured below) opened in Lexington at Harrodsburg Road (US 68) and New Circle Road (KY 4) in August 2011.