ITE Journal - August 2020 - 45

disobedience by the road users due to lack of a clear design. The
design review by stakeholders included selection and placement of
traffic control signs, markings, and traffic signal indications, and
curb details.

Project Description
Loop 820 and Marine Creek Parkway is a conventional diamond
interchange in northwest Fort Worth, TX. The off-peak traffic
volumes are relatively low in all directions, and the intersection
handles the traffic demand with minimal stops and delays.
However, while through traffic in all approaches stay relatively low
during peak hours, the left-turn volumes get heavy in all directions
with long queues. Currently, traffic signal at the intersection
operates under the four phase TTI phasing sequence (shown in

Figure 4) where each of the four approaches are served once at a
time in a clockwise pattern.
The existing geometric layout and lane configuration on
Marine Creek Parkway, which consists of two through lanes and
one left-turn lane in eastbound and westbound directions and
geometric layout, are shown in Figure 1a.
The project involves relatively minimal construction that would
end up realigning left-turn lanes. Additional modifications include
installation of new traffic signal mast arm assemblies and signal
indications for the left-turn movements.

Proposed Intersection
Flipped Left Diamond Interchange is a new and innovative intersection concept with the potential to minimize daily congestion

Figure 1a. Existing Roadway Layout: A conventional diamond interchange: Where an operating traffic signal under any phasing sequence beside the four
phase TTI phasing sequence depends on level of left-turns volume and storage capacity of the left-turn lanes.

Figure 1b. Existing Roadway Cross Section.
w w w .i t e.or g

Augu st 2020

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ITE Journal - August 2020

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