Diverging Diamond Interchanges (safer for cyclists?)

[William]

I read an article about these a while back and at first glance it looked like chaos, but after watching the YouTube tour, and reading a little more it actually makes some sense. Actually safer for cyclists, pedestrians, and drivers? Does anyone have thoughts or live near one care to comment?

Short video visual
http://www.youtube.com/watch?v=B5JtZMPTNAY

Longer narrated walking tour video
http://www.youtube.com/watch?v=YgSctDRYmdg&feature=watch_response

The claim is that they provide...
http://www.divergingdiamond.com/benefits.html

Fewer conflict points (14 for DDI, 26 for conventional)
Conflict points spread out throughout interchange
Better sight distance at turns
Virtually no driver confusion (FHWA study and new DDI observations in Springfield, MO)
Traffic calming features when desired
Wrong way entry to ramps extremely difficult
Pedestrian/cycling crossings are shorter

Unique phase combinations
“Free” or simple left and right turns from all directions
Increases left turn lane capacity without needing more lanes
Only two phases needed, shorter cycle length
Lanes with multiple assignments in all directions
Better storage between the ramp terminals
More functional during a power outage
U-turns from highway are accommodated well
Better signal network synchronization






William

[chuckroast]

Well, for what it's worth, I've driven but not cycled through the intersection in Springfield that is shown in the You Tube video (actually, I've been through it 3 times that I can remember). This particular one is on the far north edge of town and there's another one on the far south side of town as well.

It's not weird at all to drive. The traffic lights at the cross overs are long enough to get your bearings. There's enough visual and physical cues to keep you from inadvertantly going straight instead of doing the veer.

Neither one of these are on roads that I would ride a bike on though so I don't know how a cyclist would perceive them.

[tugrul]

It doesn't seem to change anything that bugs me about those intersections.

http://www.divergingdiamond.com/resources/_wsb_531x453_I-44+-+SR+13+DDI.jpg

The shoulder still disappears to make way for an on ramp to the highway and you have to take a lane or ride between lanes to go straight.

Which would be fine except for the occasional disagreeable motorist.

[reidbeloni]

Wow, this is really neat. I've seen something like this in Maryville, TN except is was a smaller intersection and seemed like more of human factor experiment. I would like to see a full size one at a highway overpass.