Diverging Diamond Interchange (DDI)
These interchanges have been shown to increase capacity and safety, decrease congestion and minimize the cost of new infrastructure.
Benefits & Advantages:
- Safety – Reduces the number of ways vehicles can collide by almost half (14 compared to 26 for a conventional diamond interchange).
- Greater capacity and efficiency – Accommodates more traffic than conventional designs. Drivers make free-flow right and left turns on to the major freeway.
- Easy navigation – Guides drivers with overhead signs, pavement marking, and traffic signals.
- Meets the needs of all road users – Accommodates large trucks, pedestrians and bicyclists.
Navigating A DDI:
- Drivers follow the signs, signals and pavement markings to cross through the intersection at the first set of traffic lights. Traffic appears as if on a one-way street.
- All left turns onto the freeway are free flow, meaning vehicles do not have to stop to access the ramp.
- Vehicles going straight simply proceed through a second set of traffic lights.
- Pedestrians travel on designated walkways and cross only at the crosswalks.
- Bicyclists may choose to use the bike lane or pedestrian walkways and crosswalks.
Cost-Effectiveness:
- For improvement projects, a Diverging Diamond interchange often uses the existing bridge structure and the existing right of way, which eliminates the cost of building new structures and purchasing additional right of way.
- Because many of the existing interchange features remain intact, the Diverging Diamond interchange is often built in less time than it would take to build a new interchange and with significantly less impact to motorists.
- A Diverging Diamond interchange usually requires the purchase of less right of way and the construction of fewer lanes and bridge structures than traditional interchange types.
Videos:
News:
Dakota News Now: What will the DDI look like when complete?