Disadvantages
- Drivers may not be familiar with configuration, particularly with regards to merging maneuvers along the left side of the roadway or the reversed flow of traffic.
- Pedestrians would be required to cross free-flowing traffic on freeway ramps. This could be mitigated by signalizing all movements, without impacting the two-phase nature of the interchange’s signals.
- Free-flowing traffic in both directions on the non-freeway road is impossible, as the signals cannot be green at both intersections for both directions simultaneously—unless the two signalized intersections are replaced with underpass/overpass structures (an expensive proposition and usually not possible within the existing right of way of the non-freeway road).
- Exiting traffic cannot re-enter the freeway in the same direction without first leaving the interchange on the crossroad. This has several implications:
- It makes it difficult to implement stops for express transit buses.
- Drivers who accidentally take the wrong exit must turn around somewhere along the crossroad.
- Emergency management cannot use the exit and entrance ramps to allow freeway traffic to bypass a crash at the bridge.
- An oversize load can not use the exit and entrance ramps to bypass a bridge that is too low.
- A diverging diamond can not be the parent interchange for a rebound interchange without using collector-distributor roads (local-express lanes).
Read more about this topic: Diverging Diamond Interchange