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Changing Lanes
- vvanders 9y agoPretty clever how they change the lanes with traffic(as opposed to against) so that their lane doesn't have a sudden, moving merge.
- ggggtez 9y agoWhat?
- jessriedel 9y agoI wonder if this means they need two vehicles for changing more than one lane, or if they just drive it back like a normal car in between two lane-moving trips in the same direction.
- wccrawford 9y agoThe article said they have 2 vehicles that can do it quickly when they need to go from 4-2 to 2-4.
- deleted 9y ago[deleted]
- ersiees 9y agoIN 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.
- konspence 9y agoSame in Vancouver, BC. The Lions Gate bridge has reversible lanes toggled by overhead signs. https://upload.wikimedia.org/wikipedia/commons/7/7e/Lions_Gate.jpg https://upload.wikimedia.org/wikipedia/commons/7/7e/Lions_Ga...
- Animats 9y agoThe Golden Gate Bridge had that for decades, but there were too many accidents. A "zipper" barrier was considered many times, but early versions weren't strong enough to stay put if hit, or were too wide, eating up too much lane width. Lake Shore Drive in Chicago had solid lane dividers which were raised out of the pavement hydraulically.[1] These didn't work reliably and were abandoned in the 1970s. [1] http://historicbridges.org/illinois/lincolnpark/ccp_passe.jpg http://historicbridges.org/illinois/lincolnpark/ccp_passe.jp...
- greeneggs 9y agoMy memory is that the Golden Gate Bridge used movable traffic cones (pylons) for decades before the current barrier system. Was there a time that lane direction was only based on overhead signage?
- Animats 9y agoPictures of the bridge show a whole range of things the Golden Gate Bridge authority tried. Solid lines for every lane. Double lines down the middle. Neon signs ("2/3/4 lanes") at each end. Traffic cones at each end to guide cars into the 2/3/4 lane arrangement. Pylons that plugged into the bridge deck. (Probably post-1986, when the bridge deck was replaced, one section at a time. and the roadway was widened by two feet.) A "zipper" movable barrier was considered several times, but early versions were too wide or not strong enough. Finally they got one that worked.
- revelation 9y agoThe 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.
- falcor84 9y agoWell, it has scaled pretty amazingly until now. It might quite possibly scale even further with the use of smaller self-driving vehicles.
- revelation 9y agoAh yes, the mythical self-driving car that solves Americas traffic problems despite being the exact size of a normal car (bigger, even).
- DKnoll 9y agoWhat's the alternative? If weight of the metal box is the problem, individual cars beat out buses and trains.
- closeparen 9y agoThe alternative is to all live within walking, cycling, and transit distance of our needs. This also doesn't work very well when we're not willing to upzone/bulldoze/gentrify existing low-density communities on centrally located land.
- YSFEJ4SWJUVU6 9y agoDon't we? Transit distance with cars, that is?
- closeparen 9y agoEvery distance is walking distance if you have enough time. By "transit distance," I mean "a distance that can be covered on public transit in an acceptable amount of time." I'd wager that for most people, this is less than half the distance they currently drive.
- cromulent 9y agoI 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.
- deleted 9y ago[deleted]
- JoeDaDude 9y agoI used to commute over one of the bridges between New Jersey and Philadelphia. The machine would be changing concrete barriers daily in the wee hours of the morning to allow one more lane for commuters going into the city, and later in the day for those returning home.
- simoneau 9y agoDo the cone-handling machines strike anyone else as over-engineered?
- jessriedel 9y agoYes. This is the kind of machine that is only ever bought with someone else's money.
- DontGiveTwoFlux 9y agoIt seems like the kind of thing that doesn't take that many fatalities prevented to break even on.
- jessriedel 9y agoThe key word was "over-engineered" not "unnecessary". There are alternatives besides having someone place cones on foot.
- taxpayer9 9y agoYes, thank you for explaining how taxation works. I thought about buying my own cone-handling machine for my libertarian utopia, but I decided to just pay a little money with everyone else to have modern amenities like road construction.
- jdietrich 9y agoNope. Manual cone handling is incredibly dangerous. At best, someone has to hang out of the side of a vehicle; at worst, they're walking unprotected next to a live lane. This work is often carried out after dark and in poor weather conditions. Automated cone handling machines are a massive advance in safety. From a purely cynical perspective, they usually pay for themselves in improved productivity and reduced insurance premiums.
- protomyth 9y agoFrom a purely cynical perspective, they usually pay for themselves in improved productivity and reduced insurance premiums. heck, it probably pays for itself by avoiding one lawsuit
- t0mislav 9y agoBtw, 99pi is great podcast.
- maaaats 9y agoDoes 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.
- InitialLastName 9y agoOften they're using these on bridges, which are narrower than the roads that feed into and out of them, and thus can act as bottlenecks. In that case, widening the direction that has more traffic can make a big difference.
- jlebrech 9y agowhy not just have leds to indicate to change lane without a physical barrier?
- dom0 9y agoBecause this is very unreliable with human drivers.
- sitharus 9y agoOne of those machines runs on the Auckland Harbour Bridge in New Zealand for peak traffic flows. https://www.youtube.com/watch?v=976rvgbX6gw https://www.youtube.com/watch?v=976rvgbX6gw 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.
- toomanybeersies 9y agoI don't know exactly why, but when I was a kid, seeing the lane-changing machine was always one of the highlights of going on a trip to Auckland.
- habosa 9y agoThe 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.
- closeparen 9y agoChicago just has permanent "reversibles" (groups of a few lanes protected by barriers) down the middle of its expressways with remotely-operated signs and gates to control their direction. Must be a higher upfront cost, but less fuss than actually moving the entire barrier every time you want to switch directions.
- bandrami 9y agoMy 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.
- kbos87 9y ago93 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 - http://archive.boston.com/news/local/massachusetts/articles/2009/03/08/high_occupancy_low_usage/ http://archive.boston.com/news/local/massachusetts/articles/... Not sure where the argument on this ended up, though I believe they are still in use.
- Theodores 9y agoI 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.