Diverging Diamond Interchange Toolkit
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Right now, there are dozens of diverging diamond interchanges (DDIs) planned for the state of Florida, including several as part of the I-4 Beyond the Ultimate projects. The first DDI in Florida opened in 2017 at I‑75 and University Parkway on the Sarasota-Manatee county line, where it's one of the busiest in the U.S. Learn more about these innovative interchanges below.

Articles

What’s a Diverging Diamond Interchange (DDI)?

Unlike a conventional interchange, the lanes in a DDI cross over to the left side of the roadway. That limits the number of traffic signal phases and allows drivers to make a left turn without crossing in front of oncoming traffic. The lanes then change back to the right side of the road. Central Florida’s first DDI opened at Interstate 95 (I-95) and Viera Boulevard in July 2019.

How to Navigate a DDI as a Motorist

The driver should proceed through the first traffic light, staying in the lane in which he or she is driving. The lane will guide the driver to the opposite side of the road. Before the lane crosses back to the right side of the road, the driver will encounter one more traffic signal.

If the driver wants to turn right onto a freeway ramp from the arterial road, the driver should use the right turn lane, just like in a conventional interchange.

When turning left onto a freeway ramp, the driver should stay in the left lane and follow the lane through the first traffic light on to the other side of the road. Then, before going through the second traffic light, the driver will turn left onto the freeway ramp.

Turning right onto the arterial road from a freeway ramp is as easy as taking a right turn at a conventional interchange. When turning right onto an arterial road, remember to yield to oncoming traffic and watch for pedestrians and bicyclists using marked walkways.

To turn left onto the arterial road, follow the left lane and, when traffic allows, take a left turn. The lanes will guide the driver from the left side of the road to the right side of the road, similar to going straight through the interchange.

How to Navigate a DDI as a Pedestrian or Bicyclist

Compared to walkways in conventional interchanges, pedestrian walkways are shorter in DDIs. When walking through a DDI, pedestrians should cross traffic on designated crosswalks to reach a median. They cross traffic again to reach the other side of the interchange.

Bicyclists have the option of either using a bike lane to get through a DDI or they can use pedestrian walkways.

How Many DDIs are Planned for I-4 Beyond the Ultimate?

As part of I-4 Beyond the Ultimate projects, six additional DDIs are currently in design for the Interstate 4 (I-4) corridor in Osceola, Orange, Seminole and Volusia counties. Those will be located at the I-4 interchanges of County Road (C.R.) 532, Daryl Carter Parkway, Sand Lake Road (S.R. 482), Lake Mary Boulevard, C.R. 46A, and State Road (S.R.) 472.

Construction of the DDI at C.R. 532 is anticipated to begin in 2021 while the DDIs at Daryl Carter Parkway and Sand Lake Road are scheduled for 2022. These innovative interchange configurations have been shown to improve safety, increase traffic efficiency, and be cost effective.

Videos

Diverging Diamond Interchanges Virtual Driving Tour of the DDI Designed for Sand Lake Road (Westbound) Virtual Driving Tour of the DDI Designed for Sand Lake Road (Eastbound) Virtual Driving Tour of the DDI Designed for Daryl Carter Parkway Diverging Diamond Interchange on I-95 at Viera Boulevard

Social Media

Did you know? #DivergingDiamonds are designed to eliminate left turn crashes. In a DDI, vehicles trade sides as interstate traffic enters or exits with a slight curve, enabling all left turns to occur without crossing opposing traffic. #DDI
A major safety benefit of a #DivergingDiamond interchange (DDI) is that it’s been proven to significantly reduce collisions. In the signalized intersection depicted below, converting to a DDI reduces the number of conflict points from 18 to 8. #DDI
To navigate a #DivergingDiamond onto a freeway ramp, proceed through the traffic light and continue in your lane, as it shifts to the left side of the road. As you drive on the left side, simply turn left onto the entrance ramp and merge onto the highway. Learn more here: I4Beyond.com/DDI
If you’re driving straight through a #DivergingDiamond, proceed through the first traffic light, staying in the lane in which you are driving. The lane will guide you to the opposite side of the road, as illustrated in the image below. #DDIWeek
When turning right onto an arterial road in a #DivergingDiamond, yield to oncoming traffic and watch for pedestrians and bicyclists using marked walkways. To turn left onto the arterial road, follow the left lane and, when traffic allows, take a left turn. #DDI
Compared to conventional interchanges, #DivergingDiamonds have shorter pedestrian walkways. When walking through a DDI, pedestrians should cross traffic on designated walkways to reach a median. Bicyclists have the option to use walkways or travel through a bike lane.

Handouts

Navigating a Diverging Diamond Interchange