The new I-84 Ten Mile Interchange in Boise is scheduled to open tomorrow, but the Idaho Transportation Department is worried it will be confusing to some drivers to navigate.
The “Single Point Urban Interchange,” also known by the not-very-attractive acronym ‘SPUI’ is controlled by a single, centrally located traffic signal. You be the judge. Watch the video and let me know if you think people will adapt quickly or if there will be some issues while drivers try to figure it out.
I like SPUIs, but they can be confusing for drivers who aren't used to them. They move lots of traffic on and off the freeway.
It's kind of like roundabouts — some people just don't like them.
It's funny you mention roundabouts @Steve, because that's the example I was going to use. Some people think they are the devil's own work until they get used to them. Both are facilities I think we will be seeing a lot more in the future though, given their safety attributes and ability to keep traffic moving.
It looks like a good design, easier to figure out than many interchanges I've seen. My only concern is will it be hard to figure where to go when there's snow covering the lane markings or at night in the rain?
That throws a new twist into things I hadn't thought of @Melissa. That interchange is going to require a LOT of signage to direct people where they need to go.
They're actually pretty straightforward to navigate. They put a lot of these in Salt Lake City when they rebuilt the freeway before the Olympics.
Here is an example of one of the Salt Lake City SPUIs.
Approaching the interchange
Traffic exits to the right
Left-turning and through traffic separate
The actual intersection
The scariest part of the whole operation is the brief moment where you're making a left turn and oncoming traffic making a left turn is headed toward you. The picture isn't great, but here's what it looks like.
Thanks @Steve! I can see how that would be scary. It's that split sescond where you would be thinking, 'Am I going the wrong way?' I'm sure once all the regular commuters get used to it things will move smoothly and folks travelling through, or new to the area, will follow the lead of the other drivers.