Diverging diamond interchanges, or DDIs, are an example of “innovative” roadway designs, which use new ways to solve old problems, but do not always make sense to the average driver at first glance. The use of DDIs worldwide is growing where limited access highways meet busy local roads.
In a diverging diamond Interchange, both directions of traffic on the non-freeway road flip to the opposite side of the road while traveling through the interchange, and then flip back to normal right-side traffic flow. This temporary switch in traffic direction means that vehicles can make left turns to enter or exit highway access ramps without having to cross oncoming traffic. Compared to a traditional diamond interchange, a DDI layout reduces the number of vehicle conflict points from ten locations to just two. Not only does this increase safety, but it reduces the number of traffic signal phases needed, resulting in higher traffic volume capacity.
While these advantages may be evident to roadway engineering professionals, conveying the benefits of DDI’s to other parties is no trivial matter, especially as their traffic side switching design can be counterintuitive. By bringing in RDV, Global-5 was able to overcome these obstacles and effectively convey the reasoning for choosing a DDI configuration to a variety of project stakeholders and the broader public.