Home / Blog / Georgia DOT Digging for Diamonds Across the…

Georgia DOT Digging for Diamonds Across the State

If you’ve been frustrated by heavily congested traffic in Gwinnett, Cobb and Chatham counties, the Georgia Department of Transportation wants you to know that relief is on the way, in the form of Diverging Diamond Interchanges (DDIs). The GDOT has four projects under design or construction, following the successful introduction of two DDIs in DeKalb and Gwinnett counties.

These interchanges are an alternative to conventional highway intersections that suffer gridlock and present accident risks to motor vehicles, bicyclists and pedestrians. The DDI has the same basic diamond layout as a conventional freeway interchange, which allows right-turning traffic to flow as usual. But left-turning traffic is guided gently across the interchange on the left side of the road, before switching back to the right side of the road on the other side of the interchange. This eliminates left turns, which pose a great risk of deadly broadside crashes.

Important features of the DDI include:

  • Reducing conflict points in the traffic flow from an average of 26 to 14
  • Decreasing the speed at which conflicts happen
  • Offering safe accommodations for pedestrians on medians and along the side of the road
  • Making wrong-way entry onto ramps extremely difficult

The DDI achieves these benefits with minimal driver confusion. Many drivers don’t even notice they are driving on the left side of the road for a brief period of time. Traffic flows better across a DDI due to:

  • Fewer stops
  • Reduced stop times
  • Shorter queue lengths

The result has been a reduction in delays by 16 to 60 percent. We can look for many more DDIs in the future; modifying conventional diamond interchanges is cost-effective because DDIs can usually be built on an existing bridge deck. When a new interchange must be built, it requires fewer lanes than a conventional diamond interchange.

McMenamy Law LLC welcomes design innovations that help keep people safe in traffic. But if you’ve been seriously injured in a car accident, contact us right away to schedule a free consultation.