Green Wave(en.wikipedia.org)
en.wikipedia.org
Green Wave
https://en.wikipedia.org/wiki/Green_wave
55 comments
> ..., wastefully approaching each red light far too fast, ...
Oh, you want to save gas? Joke's on you:
> 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.
Oh, you want to save gas? Joke's on you:
> 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.
There were people in your wave who would have slowed down too much if those cars running ahead were in the pack.
I 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.
You can't really fault people for driving myopically if they don't have high level information.
That might work, though few drivers in the U.S. heed speed limits even in construction and school zones, where there are typically large brightly-colored signs and flashing lights and the stakes are much higher.
Also, since the bad behavior on display at the front of a green wave is pervasive in pretty much all traffic scenarios, it seems like a modicum of driver training might ultimately be the most foolproof approach.
Also, since the bad behavior on display at the front of a green wave is pervasive in pretty much all traffic scenarios, it seems like a modicum of driver training might ultimately be the most foolproof approach.
With the risk of sounding cynical, I think drivers will be much more receptive to being told "you can get home faster if you follow the rules" than being told "you're increasing the risk of getting into an acceident if you don't follow the rules"
>That might work, though few drivers in the U.S. heed speed limits even in construction and school zones,
Because there's nothing in it for them.
Most school zones don't have kids anywhere nearby outside two specific times of day.
Most construction zones don't actually have construction happen.
Many posted speed limits are either artificially low by statute (state laws to the tune of "if road has X then max speed limit = Y" are common), for revenue purposes or to account for a temporary condition that does not affect the entire area where the speed limit applies (e.g. a single tight curve or trucks enter/exiting during business hours).
In light of these it's no wonder so many drivers disregard posted limits since it allows them to get to their destination faster.
If drivers knew that a particular travel speed would result in hitting all greens then you can bet your ass the majority of them would drive that speed. There's a ton in it for them.
Because there's nothing in it for them.
Most school zones don't have kids anywhere nearby outside two specific times of day.
Most construction zones don't actually have construction happen.
Many posted speed limits are either artificially low by statute (state laws to the tune of "if road has X then max speed limit = Y" are common), for revenue purposes or to account for a temporary condition that does not affect the entire area where the speed limit applies (e.g. a single tight curve or trucks enter/exiting during business hours).
In light of these it's no wonder so many drivers disregard posted limits since it allows them to get to their destination faster.
If drivers knew that a particular travel speed would result in hitting all greens then you can bet your ass the majority of them would drive that speed. There's a ton in it for them.
Agreed, I once had to tell an out of towner "just drive the speed limit, you'll get all green lights."
I'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.
At 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
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
The speed varies based on who's timing the lights.
Where I am there is the problem that in any more than the lightest amount of traffic, the cars queued up at a red take too long to get up to speed, so you end up getting only 2-3 intersections of green before stopping because you never reach the speed-limit.
Even when cars do get up to speed, there's things like turning traffic vs. pedestrians. I suppose if they eliminated on-street parking and had dedicated turn lanes for both directions, it would work, but that's not happening any time soon.
I can actually make it down the entire length of a 1-way by going 25mph (the speed limit) and weaving between cars like a maniac, but that seems rather unsafe (not to mention illegal).
Even when cars do get up to speed, there's things like turning traffic vs. pedestrians. I suppose if they eliminated on-street parking and had dedicated turn lanes for both directions, it would work, but that's not happening any time soon.
I can actually make it down the entire length of a 1-way by going 25mph (the speed limit) and weaving between cars like a maniac, but that seems rather unsafe (not to mention illegal).
Great 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
[0] https://en.wikipedia.org/wiki/Great_Highway
This 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".
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".
It 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.)
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.)
NYC 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).
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).
Sadly, our green wave is synchronized with a 50 mph speed, but the posted (and reasonable) limit is 35 mph.
Obligatory XKCD Reference
https://xkcd.com/277/
https://xkcd.com/277/
I only ever experience red waves.
Love when I get these. Give me more!
> 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.
Lovely.
Right? 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.
Tax 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.
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.
I 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.)
You 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
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
Showing 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.)
(...and, yes, it's upsetting that this happened in real life.)
I 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.
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.
As 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").
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").
The 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.
That'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.
Not having to waste your momentum is really, really nice on a bike. I always resent stop signs at the bottom of a hill.
If it gets more people to bike instead of drive, it still has those benefits.
You're absolutely right. I didn't think about it like that, thanks.
Making 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.
Also works really well here in Copenhagen to get to/from the city centre during rush hour.
On 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
Were 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.
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.
This 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.
Remember folks: lights timed for 40 are also timed for 80. /s
Suppose 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.
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.
I think the parent is referencing this:
http://www.bash.org/?5483
I remember reading this quote more than 10 years ago and still occasionally think about how wrong it is.
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]
Taking 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.
My 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.
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.
Do 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.
Lastly, the emergency vehicles use pulsed light which have a different sensor pointed towards the traffic and not the other direction.
No sources other than observations from myself and all of my friends and family going to work the same route every day.
I would be happy to capture some video though. Driving on long streets after hours it is especially noticeable.
Best 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.
Folsom 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.
I 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.
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.
These 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.
My 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.
Two 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. :|
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. :|
I 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.
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.