One of those machines runs on the Auckland Harbour Bridge in New Zealand for peak traffic flows. <a href="https://www.youtube.com/watch?v=976rvgbX6gw" rel="nofollow">https://www.youtube.com/watch?v=976rvgbX6gw</a><p>It used to be just sign controller (the signs are still there) but people are bad at observation. Even now when they have a gradual lane closure people still get 'caught out'. There's about 2km notice of which lanes are open.
I worked on a toll road construction project 10 years ago and the guys there subscribed to some sort of trade magazine. It had a barrier transfer machine on the cover that moved the concrete Jersey barriers across one lane as it drove along. Amazing stuff. The zipper format is even better.
IN Germany there is a similar thing. Instead of having a barrier, they have lights to indicate which paths who can use and change them according to traffic.
93 in the Boston area has had median movers in place for a long time. Back in 2009, they were 14 years old, and their value was being questioned at $1 million each to open and close an under-used HOV lane -<p><a href="http://archive.boston.com/news/local/massachusetts/articles/2009/03/08/high_occupancy_low_usage/" rel="nofollow">http://archive.boston.com/news/local/massachusetts/articles/...</a><p>Not sure where the argument on this ended up, though I believe they are still in use.
I like the contrast with the British cone collecting machine and how well that works in reality. If you watch the video of the TrafTech cone collecting machine to the very end you will see how it fails on the last cone with the machine jammed up.
The only two places I've ever lived (Philadelphia are and San Francisco) both have this machine so I assumed it was extremely common. Only realized from these comments that it's not.
Does increasing nr of files of the roads actally increase throughput noticeably? From my experience it's the intersections or traffic from exits that is the problem.
My daily commute has me pass one of these most days (DC Roosevelt Bridge in the afternoons.) The amount of mass being moved right next to you can be unnerving.
The silly stuff we keep inventing to not confront the simple truth that single persons sitting in 2 ton metal boxes on highways leading to city centers is insane and will not scale.