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Green Wave
- izzydata 7y agoI only ever experience red waves.
- stoltmeister 7y agoLove when I get these. Give me more!
- GrayShade 7y ago> In the UK, in 2009, it was revealed that the Department for Transport had previously discouraged green waves as they reduced fuel usage, and thus less revenue was raised from fuel taxes. Despite this government Webtag documents were only updated in 2011. It is still unclear if the economic appraisal software used to apply these guidelines has also been updated and if the new guidelines are being applied to new projects. Lovely.
- Xophmeister 7y agoI wonder what would be the better pay-off on aggregate: more tax revenue from extra fuel use or -- presuming people get to where they need to be more efficiently -- more tax revenue from the increased productivity/consumerism? I wonder which is better in terms of pollution and other potential negatives? So, which is net cheapest? (My money's on green waves.)
- ghostbrainalpha 7y agoYou are assuming increased taxes from productivity/consumerism would affect the Department of Transportation's Budget. They overvalue fuel tax specially because a portion of it is earmarked directly to them. This was real by the way, not just a libertarian talking point. http://news.bbc.co.uk/2/hi/uk/7998182.stm http://news.bbc.co.uk/2/hi/uk/7998182.stm
- Xophmeister 7y agoShowing my ignorance, but I didn't even realise that tax revenue from a certain stream (e.g., fuel tax) went directly to the government department (e.g., DfT) that instigated it, rather than it being absorbed centrally by the treasury and then redistributed according to fiscal policy. That's interesting. Doesn't that mean that certain departments will be more flush with cash simply by virtue of attracting more tax? (...and, yes, it's upsetting that this happened in real life.)
- axaxs 7y agoRight? Every fiber of my body screams "JUST INCREASE THE TAX!". Figure out the fuel usage drop, if any, and adjust the tax accordingly. Hell, I'd pay double fuel taxes if I didn't have to fight red lights anymore.
- sneak 7y agoTax revenues won’t be very helpful when there are mass crop failures and hundreds of millions starving or thirsty due to climate change. This isn’t about money, it’s about the inherent shortsightedness of and staggering destruction wrought by bureaucrats of any country when they are given incentives of any kind. See also: private prisons, snake/rat bounty, et c.
- OliverJones 7y agoAs policies move toward taxing fossil-carbon use aggressively enough to drive reductions, this unintended consequence could prove very troublesome. Competently handled green waves will save transport energy from all sources. And, this kind of thing cries out to be integrated with adaptive cruise control (yeah, Elon, the thing you call "autopilot").
- stareatgoats 7y agoI am all for government taxes, government bodies that oversee food production and commerce, social welfare programs or lay down ground rules for various social activities. It doesn't mean that I think the government totally altruistic, and working solely common good. There is often (or always) a relatively hidden agenda which is conflated with the by all means honorable motives, like covering the costs of public services, saving the climate, or protecting us from a foreign adversary. Seldom does the ulterior motive reveal itself so clearly as in this case however. Instead thinking this is a one-off, we should really be inspired to produce or look for a service where all policy decisions were inspected not only on the aspects that the politicians or public servant say but all relevant aspects, to find out the other reasons (not necessary more "real", but relevant too). Somewhere deep among those other reasons there may be an effect that is actually not for the common good.
- sjmulder 7y agoThe town where I live (in the Netherlands) has green waves for cyclists. It's lovely to experience and also a good way for the council to encourage this sustainable, healthy mode of transport.
- simongray 7y agoAlso works really well here in Copenhagen to get to/from the city centre during rush hour.
- acidictadpole 7y agoThat's really cool. Though it does seem to remove almost 50% of the benefits listed in this entry, but those seem to be focused on fuel-consuming vehicles rather than bikes.
- lkbm 7y agoIf it gets more people to bike instead of drive, it still has those benefits.
- acidictadpole 7y agoYou're absolutely right. I didn't think about it like that, thanks.
- CalRobert 7y agoNot having to waste your momentum is really, really nice on a bike. I always resent stop signs at the bottom of a hill.
- huebomont 7y agoMaking biking preferable and easier and faster is a great way to reduce fuel consumption by getting people out of cars and onto bikes. The best way to reduce fuel consumption is to make driving undesirable.
- papreclip 7y agoOn my previous commute home, the green wave seemed to only work if you travelled 85 or 30 mph (posted limit 55), everyone else got hit with every red
- lkbm 7y agoWere you travellng the opposite direction of most commuters? Green wave only works in one direction. fwiw, that's one benefit of one-way roads -- they each can be programmed to ensure a green wave for all cars on them. I never understood why you'd want a one-way road (outside small neighborhood streets) until my friend pointed that out.
- tomphoolery 7y agoThis is why I always took W Passyunk Ave coming home from work when I lived in South Philly. If you travelled at around 20-23mph, you'd hit green lights from the moment you got off the highway to the street you had to turn on. It was great, but since nobody knew about the concept you'd have a lot of people frequently stopped in the middle of the street or not moving at the right speed. I wish this was more common so it would be taught in driver's tests or something, that way people would drive slower in these areas and also get to where they need to go quickly.
- throw0101a 7y agoRemember folks: lights timed for 40 are also timed for 80. /s
- maest 7y agoI think the parent is referencing this: http://www.bash.org/?5483 http://www.bash.org/?5483 I remember reading this quote more than 10 years ago and still occasionally think about how wrong it is.
- deleted 7y ago[deleted]
- ambrop7 7y agoSuppose the the period of lights is equal to the time expected to move from one light to the next, and each light is red/green for the same amount of time. You have a green wave if you pass the first light green and drive at the expected speed. But if you drive twice as fast, you reach the second light red instead of green. Now it would work if the period of lights was half the time expected to get from one light to the next, but why would that generally be the case? Actually I think the opposite will usually hold: you will still have a green wave if you drive at the expected speed divided by an integer.
- alamortsubite 7y agoTo help pay for tuition, one summer I drove a university shuttle in the evenings after finishing my work-study job. At that time, the lights on Walnut and Chestnut streets in West Philly were set up with green waves. The best place to ride the wave was obviously at its tail, entering each intersection a little before the light would turn yellow. Traffic there was light-to-none, and its flow far smoother and safer than at the front, where there were usually drivers pointlessly fighting to maintain their positions. I would watch them all just up ahead of me, wastefully approaching each red light far too fast, braking hard until it turned green, then rapidly accelerating to the next, repeating this insane processes intersection after intersection for a dozen blocks at a time, like some sort of mobile psychology experiment gone wrong. Because I was naive, I thought poorly of Pennsylvania drivers. Later I moved to SF and experienced the same thing on Franklin and Gough, and realized the phenomenon was probably fairly universal. Green Waves could be a great thing, but there's still the unsolved problem of human beings behind the wheel.
- maest 7y agoI think this phenomenon shows the importance of communicating to the drivers that a green wave system is in effect. You can't really fault people for driving myopically if they don't have high level information.
- gwbas1c 7y agoAgreed, I once had to tell an out of towner "just drive the speed limit, you'll get all green lights."
- ttymck 7y agoI've noticed (because I once read somewhere) that driving 5-10mph _over_ the limit results in the best timing. This is in both Pennsylvania and Los Angeles.
- cuddlybacon 7y agoAt one time a particular subreddit* was quite insistent that it is always the case that going the speed limit always results in the same commute time as speeding. No matter the city. I tried it in Vancouver, and my commute went from 45 mins to 65. The bulk of traffic does 5-10km/h over the limit, so perhaps traffic light timing is based on that. * Reddit is blocked at work, but it was probably something like r/townplanning
- PaulBGD_ 7y agoTaking Portland Ave and Park Ave are great in Minneapolis, but I agree about cars in the front speeding, slamming on their breaks for the red, the going again. I wonder if there should be a new sign for green waves, or maybe we could just make them more popular.
- sixothree 7y agoMy city has lights timed to ensure that signals turn red just before the wave of traffic reaches it. You can see the signals have antenna on them pointed at the next intersection. It is infuriating on a level I can't describe. My guess is they are trying to reduce accidents or they are trying to make more tax money by getting people to burn more gasoline.
- alamortsubite 7y agoDo you have a source for this? Driving in city traffic can be frustrating, but I wonder if the antennas you see are for emergency vehicle signal preemption, or serve some other purpose.
- sixothree 7y agoNo sources other than observations from myself and all of my friends and family going to work the same route every day.
- sixothree 7y agoI would be happy to capture some video though. Driving on long streets after hours it is especially noticeable.
- sixothree 7y agoLastly, the emergency vehicles use pulsed light which have a different sensor pointed towards the traffic and not the other direction.
- sjlogan 7y agoBest green wave I have ever experienced is going north on 10th ave in NYC. You can drive for 100 blocks without stopping if there isn't too much traffic and you time the lights correctly.
- acheron9383 7y agoFolsom street in the Mission District of SF has one at 15mph. Perfect if you are on a bike. Keeps the average speed of drivers down in the residential areas, and if you know the timing is at 15mph, you might as well just cruise.
- Brendinooo 7y agoI always appreciated this on the University of Pittsburgh's campus, and was really happy when they did it in my current hometown. I used to take back roads and take my chances with speeding and stop signs, but now I find myself taking the main road way more now because I know I'll probably only stop at one light maximum, and I know how to time my driving.
- dsego 7y agoThese don't work in my city because everyone just rushes to get to the lights first and come to a full stop. Then those stopped cars take their time to speed up again.
- jcrawfordor 7y agoMy city has posted signs indicating the "green wave speed" in a few spots and it actually seems like a more effective form of traffic calming than speed bumps or forced turn obstacles.
- aaroninsf 7y agoTwo green wave examples I value in San Francisco: 1) the Valencia bike commute green wave (named as such with posted speed) When it's broken for some reason it's very noticeable and unfortunate. 2) the various coordinated designated auto throughways which make up for the lack of in-city access freeways Except when you're going against the direction, like when my wife was in labor. :|
- tus88 7y agoI live in a city where the traffic engineers are too stupid the understand the value of this...about 50% of the time I get a green light, only to immediately see the next light go red about 100 meters away. It's infuriating.
- GistNoesis 7y agoThis one sent me quite down the memory lane. Back in 2009, I realized a fake-iphone app pitch where the goal was to sync your music so that you can ride the green wave as a pedestrian. The music will slow down or accelerate so that by walking to the beat it guarantees you that you will go with the flow. As it was just for a pitch, I realized a video (with the help of a friend checking for my safety) to showcase the usage : Two long-sequence shots of walking between two places in Paris and being sure to have only green lights, like 15 green lights total to be nailed when they are clearly not synchronized for you and there is people and traffic around. It was an experience in the spiritual line of Claude Lelouch "C'était un rendez-vous".
- cafard 7y agoIt used to be that an MPH or two under the speed limit would get one halfway across Denver without stopping for a light. That was a long time ago, though. I don't drive much these days. In Washington the traffic levels can be such that the best timing in the world won't set up a green wave. On the other hand, I do manage now an then to make it half a mile or so as a pedestrian without stopping for a light. (On 16th St. NW from U to Scott Circle, a saunter will hit all the lights green; a fast walk might do the same, but I seldom bother to try that.)
- ivanech 7y agoGreat Highway [0] in San Francisco is my favorite example of this. If you drive precisely 35 mph, you'll hit green lights for about two miles. This works in both directions. I think it's possible because the lights are to allow pedestrians to cross the road, so there are no intersections with cars for the full two mile stretch. Still, I think it's a lot of fun. [0] https://en.wikipedia.org/wiki/Great_Highway https://en.wikipedia.org/wiki/Great_Highway
- quartz 7y agoNYC has a bunch of these on most of the avenues that break down at rush hour but work pretty well at other times, especially on weekends when you can do miles at a time. You can actually watch the downtown wave approach and pass when you're going uptown on Park Ave starting around 60th St (and you'll get to watch it many times as you constantly hit red lights since you're fighting the wave).
- daveslash 7y agoObligatory XKCD Reference https://xkcd.com/277/ https://xkcd.com/277/
- kakuri 7y agoSadly, our green wave is synchronized with a 50 mph speed, but the posted (and reasonable) limit is 35 mph.