Diverging Diamond Interchanges: Navigating DDIs with Safety and Ease

A diverging diamond interchange (DDI) is coming to the Interstate 4 (I-4) and Sand Lake Road (State Road (S.R.) 482) interchange. Although the completed DDI will take some time for construction, the project will adopt an initial DDI configuration in early 2024 so that crews will have space to work on the bridge over Sand Lake Road.

In anticipation of drivers’ questions regarding the initial DDI in this busy interchange, below are some facts, benefits, and guidelines for navigating DDIs.

The DDI Basics

DDIs are part of an innovative interchange configuration that cost effectively improves safety for drivers while improving the flow of traffic. The lanes in a DDI cross over to the left side of the roadway to reduce the number of traffic signal phases. DDIs also allow drivers to make a seamless left turn without having to cross in front of oncoming traffic. The lanes then return to the right side of the road at a traffic signal on the other side of the interchange.

The Benefits of DDIs

  • Safety: DDIs reduce conflict points (places where vehicles must merge or cross in front of each other) by 50 percent compared to a conventional interchange.
  • Cost: Because DDIs generally require less right of way to build, they are more cost effective to construct than some other types of interchanges.
  • Efficiency: By design, DDIs have fewer traffic signal phases, which helps to reduce congestion and move higher volumes of traffic.

As the initial DDI coming to Sand Lake Road in early 2024 moves to transform traffic along the area, below are some easy-to-follow guidelines based on entry and exit points to get you and your loved ones safely to your destination.

Navigating the DDI

  1. Approaching a DDI, drivers should proceed through the first traffic light, staying in the lane in which they are driving.
  2. The lane will guide the driver to the opposite side of the road. Drivers should pay attention to signs and pavement markings. Before the lane crosses back to the right side of the road, the driver will encounter one more traffic signal.

Entering I-4 from Sand Lake Road

  1. Drivers who want to turn right onto I-4 from Sand Lake Road should use the right turn lane, just like a conventional interchange.
  2. When turning left onto I-4 from Sand Lake Road, the driver should stay in the left lane and follow the lane through the first traffic light to the other side of the road. Then, before going through the second traffic light, the driver will turn left into the I-4 entrance ramp.

Exiting I-4 onto Sand Lake Road

  1. Turning right onto Sand Lake Road from one of the I-4 exit ramps is as easy as taking a right turn at a conventional interchange. When turning right onto Sand Lake Road, remember to yield to oncoming traffic and watch for pedestrians and bicyclists using marked walkways.
  2. To turn left onto Sand Lake 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, as if going straight through the interchange.

To learn more about the DDI project at Sand Lake Road, please visit: I4Beyond.com/SandLake.