
Diverging Diamond Interchange comes to Washington State (2016) [video] - anonu
https://www.youtube.com/watch?v=5gLxlXamhgY
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gmiller123456
Unfortunately everything I've seen about diverging diamonds appears to me to
be more like a marketing campaign for it rather than actual information. They
only talk about the positive points of it, and only in abstract terms like the
number of conflict points and number of traffic light phases.

It seems to me it's trading a separate phase for the left turns, in favor of
"everybody has to make a left turn", and those wanting to proceed straight
also have to cross traffic again. So I'd imagine this probably does work
better for people who wanted to turn left, but worse for people that wanted to
go straight.

And during low traffic periods, anyone wanting to go straight will have to
stop at two lights rather than just having the lights default to green unless
a car shows up at one of the sides.

Maybe they're better, maybe they're worse, but more likely it depends on a lot
more things than this video lets on.

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justinator
Looks like a pedestrian would have to cross 4 segments of road to just get
across the street instead of one? The vid. sort of yadda yadda'd that part.

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notatoad
four crossings instead of two, not four instead of one. unless you're simply
crossing the cross street, and not actually crossing the highway, which there
isn't really any reason a pedestrian would do at that at that intersection.

making two 36' crossings is a lot safer than a single 72' crossing. narrowing
the crossing width is a good thing in intersection design, even if it takes a
bit longer. It's a fairly long walk for for a pedestrian to make, waiting for
an extra light isn't going to make a significant change to the crossing length
for a pedestrian.

