0277: "Long Light"

[notzeb]

Amazing. Something about that punchline hit me real hard in the funny-bone. Could this be the first time I've experienced a true human emotion?

[liza]

This comic will be especially ironic on Tuesdays, since the engineer's answer would be equivalent to saying "in the future", or "sometime".

Gotta love time-lapse irony. Not to mention cyclical semi-self-reference.

[gtkarber]

My granddad--my Papa, as I have said since I could articulate words--is a former police officer/FBI agent, and for some reason he has said to me before, when we were at a red light, that they should let the police officers do the timing on the stoplights.

"The police officers?" I said.

"They're the ones who know the traffic best," he replied.

"Not the civil engineers?"

"No."

"Not the people who went to school to train to do this?"

"No."

It's impossible to argue with the man, and he might carry a gun, so that's all that I said, but I wanted to ask how many fucking seconds he thought a long time would be, and how many seconds was a short time, and how they should rotate, and if he knew how multiple street lights in a town should interact, but of course I didn't, because you never ask a rhetorical question to someone steadfast in their beliefs: it only influriates them.

[quintopia]

I can't say this has never happened to me before, but I learned my lesson after that one time before I discovered how frelled up those lights right there are.

Glad to see other Farscape fans on xkcd.

I tried it once a while ago with a black charger... sorta ended in tragedy.

That's what you get for challenging a ricer with a muscle car.

BTW, I think the timing of this light wasn't the most frustrating part of this engineer's job. More likely, it was designing a traffic light that would float in mid-air with no visible means of support. Imagine the guys at the Dept. of Roads when they got that work order. . . .

[nicooo]

I remember reading about a city using bus schedules to change the lights on roads where the busses are running late. Apparently this helps traffic flow more easily. Now I can't seem to find the article anywhere.

[iw]

Great. I'll be living in Valpo before too long. Thanks for giving me something to look forward to.

Wow, I didn't expect people from Valpo to actually be on here! Why are you moving there? (btw the intersection is now fixed; they made the south->north lanes 3 wide, so there's a left, straight, and right turn lane.)

[iw]

I remember reading about a city using bus schedules to change the lights on roads where the busses are running late. Apparently this helps traffic flow more easily. Now I can't seem to find the article anywhere.

It sure as hell ain't Chicago.

[|333173|3|_||3]

I'll admit to getting frustrated when no matter how many times you hit the "walk" button, the light won't even start to change until a car pulls up, going the same direction as you.
I walk everywhere, so long lights just prompt jaywalking.
(And even EXTREME JAYWALKING. It's like a city-wide sport.)

There is nothing I hate more than when someone pushes the buttons and then walk anyway before the light changes. I say this as someone who walks more than he drives.

After getting that off my chest, i frequently think about how complicated it must be to time traffic lights correctly

A significant percentage (I don't want to say a majority) of crossing buttons, especially in large cities, are essentially "electronic placebos". They don't speed up or alter the change pattern at all, they just make the person standing at the crosswalk feel better and like they have some control over the happenings of the light.

Ever tell people that if you push the button 256 times it makes the light change faster? it's hilarious how many people start counting...

Actually, in South Australia a lot of the older pelican crossings are not linked into the main light network, and will crash if you press the button four times, switching to the pedestrians. Unfortunately, the newer ones have been fixed, and so won't change if you do this. Nonetheless, most Adelaideans will press the button four times whenever they reach a crossing.

The main questionable manoeuvre used here is to pull into the junction to turn right while it is impossible to get out (which is illegal), and wait for the lights to turn red before turning right and continuing the journey. It is illegal to pull into a junction which you cannot drive out of, but this rule is never enforced, and even police flagrantly disobey it.

Here the traffic lights are controlled by a dial-up network which the emergency service controllers (the people who respond to 000), and the emergency services have access to, as well as the transport people responsible for the lights. A friend of mine did work experience with the company which has the maintenance contract on the computer systems, and explained it to me. I have started on a program to search the on-line White Pages (less duplicates than the yellow pages), and find all the in-use phone numbers. Since the traffic lights are mostly in a large block, with the serial number forming the last part of their phone number, hopefully I can find their numbers and try to figure out he communications protocol. If I manage that, it would be a simple problem to connect up a GPS system to a laptop, connect that to a mobile phone, and thus change the lights on approach.

[Patren]

Anyway, aren't most lights nowadays have a IR override system built into them? Emergency services, i.e. EMS, P.D., use it to change the lights to allow the quickest arrival to a destination.

I've heard(meaning I can't exactly vouch on the reality of this statement) that there are sensors that will turn the light green in reaction to the strobes on the emergency vehicles. Which means that you can easily simulate this by flashing your high beams. Now, the problem with this, and why my informant(aka brother) knew about this, is that when the emergency vehicles force the light to change green, the opposing lights switch straight from green to red. Where my brother lives, someone was going around forcing the switch with their lights and had caused multiple accidents.

On pedestrian crosswalks
The ones where I live are perfectly designed...too perfectly. I know when I'm walking to Wal-mart at 3 in the morning that when I push the button, unless there is a car immediately at the intersection, the lights will change to my favor. I cannot tell you the temptation I get when I'm at those lights to just stand there until I see a car coming and then push button, forcing the person to have to stop at a well-timed light at three in the morning.

[Belial]

http://www.snopes.com/autos/law/strobe.asp

[Tomcat]

I don't think you understand what really happens when products like that are built. I can pretty much guarantee that the engineer did not want to design it that way. It's their managers. See, the engineer comes to his boss and says, "If we do it this way, this will make the product ten times better." The manager says, "But that cost 0.01% more, so that cuts into our profits and we aren't going to do it that way." Or better yet, the engineer takes it to his boss and his boss says, "I thought it was good enough so I went ahead and put it in production." Or even better, "I have a 'well-rounded' liberal arts education so that makes me smarter than you. We will do it my way."
This happens more than you would think.
Dilbert is too close to real life.
I'm not cynical or anything.

This.

(I've always wanted to say that)

At my previous job, they plucked some lifetime academic out of a canadian university and made him the head of my newly-formed division in Bombay (he was an Indian who did his post-doc there).

The man is completely clueless about how the real world works. He took a decision that the next product we would design would be completely built from off-the-shelf parts and no electronics would be designed in-house. Never mind that if it was so easy, anyone else would have done it - there was a *reason* only a handful of companies in the world offer the product we were trying to build.

THEN he goes and sets a deadline of December, in August. I saw the notice - you'd think something as important as a deadline would be decided by the team - and remarked, "2007?" Then someone pointed out the "2006" to me. Last I heard, the hardware wasn't ready (two months ago), let alone the software.

I wouldn't know, I quit in October. He packed me off to a place near Delhi and expected me to sit there and forward queries from one dept to another. I'll be damned if I got a degree in Electrical for that work.

Not that I'm bitter...

Wow, I bet you've heard some interesting discussions. Most stuff I've seen "designed" by architects clearly illustrated that they thought they were engineers, but were not. It's kind of sad really.

You bet Dad often bristles when the architects change the design in the middle of the structural design, either on their own whims or due to idiotic demands by clients.

But he does grudgingly admit that you can't really replace architects as if an engineer designed buildings, they'd all be rectangular blocks for ease of design, and not something that looks aesthetically pleasing.

At least my parents did not work together!

[trentblase]

Along the same lines...
I find myself annoyed with whoever designes the seating layout on public transportation buses. Every time I ride one I find myself coming up with five or six different ways to arrange the seats so that there are more. (and yes, my designes are all handicapped accessible).

More seats probably means fewer total bus capacity (seats + standing room). The biggest problem with faulting designers in this way is that you rarely know the constraints they had to deal with. For example (mentioned in this thread), in traffic planning, often safety wins out over efficiency, evidenced by light patterns designed to limit your speed.

[himseelf]

They replaced the lights with the stupidly long waiting times with new fancy IR sensor ones outside my flat. And left the old ones sitting in the street.

Upshot is, I now have a set of 5' traffic lights in my living room.

PS Hello, I'm new.

[GhostWolfe]

Welcome New, you might want to drop by our intro thread as you probably don't want to be called "New" for the rest of your stay

[chishm]

I don't know about your city/country, but we have a lot of round-abouts in Canberra, Australia. They work on the "give way to the right" principle - you have to give way to any traffic already on the round-about, or any traffic approaching from the right (assuming you haven't entered yet). Yes, we drive on the left in Australia, it's to counter the opposite Coriolis forces we experience due to our upside-down gravity, but I digress.

Round-abouts work well, until you have heavy traffic coming from the right and you want to enter it. There was one round-about near my house where people figured they could take a slightly longer road to approach it but then they could enter on the side right of the main traffic flow, getting them through much quicker. This was okay at first, until many people did it. Eventually the main traffic flow was so impeded that - wait for it - they stuck a traffic light on the alternate entrance. Everything works again, all thanks to a single traffic light that only operates during peak hours.

Also, there is a traffic light (unrelated to the round-about) around here that has a broken pedestrian-button. You have to jay-walk, otherwise you won't get across, unless someone pressed the button on the other side. I see people waiting for the lights to change as I approach. I just keep walking across the road (is it geeky for me to know the patterns and timing of all the traffic lights in my area?) and push the button on the other side for them to get across.

[Ghona]

I'm surprised nobody else has mentioned the possible pun in the title.
Red=longer wavelength.

A significant percentage (I don't want to say a majority) of crossing buttons, especially in large cities, are essentially "electronic placebos". They don't speed up or alter the change pattern at all, they just make the person standing at the crosswalk feel better and like they have some control over the happenings of the light.

Same thing with the "close door" buttons on most elevators.

[Tomcat]

Ghona, that is creepy - I just tested it out with the building elevator because I suspected the same. I was alone in it so stopped at two floors and timed the door intervals with and without pressing the Close Door button and the times were the same

[Ronfar]

I've had a few instances of wanting to "talk" with the engineer of certain products (*cough*clamshell packaging*cough*).

Clamshell packaging is designed for the benefit of retailers, not consumers. It shows off the product inside while not allowing it to be exposed to "sticky fingers". The fact that it's so hard to open is not a bug, it's a feature.

Also, my town has what has to be one of the world's longest lights. (I timed it at over a minute.) It makes sense that it's so long given the traffic patterns there, but it's really annoying when you're on the wrong side of it.

Route 18 in New Jersey has some of the country's worst traffic jams. Rush hour starts at about 3:00 PM and ends at 7:00 PM and features miles of bumper-to-bumper traffic. Recently, the state government has invested in a massive construction project to eliminate many of the red lights along the way and improve traffic. It's not nearly complete, but it's definitely made a difference in the traffic near Rutgers University. Maybe, when it's all finished, the traffic will be ordinary bad traffic instead of world-class bad traffic.

So do you Americans not use those fancy magnetic car-sensing things embedded in the roads? They seem to be quite common here in Canada.

Some roads do (like the aforementioned Route 18) but it's not that common.

[Kawa]

http://www.snopes.com/autos/law/strobe.asp

http://xkcd.com/c250.html

[Cyberax]

Also, my town has what has to be one of the world's longest lights. (I timed it at over a minute.) It makes sense that it's so long given the traffic patterns there, but it's really annoying when you're on the wrong side of it.

A minute? There are 10 minutes traffic lights in Moscow, and I think it's hardly the longest possible time.

[Ronfar]

Also, my town has what has to be one of the world's longest lights. (I timed it at over a minute.) It makes sense that it's so long given the traffic patterns there, but it's really annoying when you're on the wrong side of it.

A minute? There are 10 minutes traffic lights in Moscow, and I think it's hardly the longest possible time.

TEN MINUTE TRAFFIC LIGHTS? HOLY [CENSORED]!!!

[xygonn]

All traffic lights should have sensors during non-peak hours. Timing all lights all the time is stupid like a non-adaptive mesh. Even better, if the sensors realized whether the traffic was heavy and from which direction to set themselves to sensor or timed in whichever direction as necessary. Adaptive things make me soooo happy.

[finale]

Problems of this sort occur on multiple levels of the structure they exist in. My father was the Director of planning for a county off the DC Beltway for a few years, and difficulty usually stems from interaction between groups, as different priority sets come into play. Urban sprawl and rapid development systems make everything worse.

It's worth noting that although sometimes managers, architects and "lifelong academics" are the folks that screw things up, ineptitude occurs at all levels- Traffic engineers can be lazy, planners can be overly inspired, and specialists in the field can forget real-world complications. So remember, although they don't always succeed,

Architects are trained to make buildings that work first and are pretty second(and there can be material benefits to 'pretty' buildings, of course).

Managers weren't always managers, and their moral balance between profit and product is often determined by the company environment that produces them.

And liberal arts school graduates are above all else supposed to have learned that knowledge from people in other fields is useful, and to keep open minds. When these people fail to make the right choices, in design, oversight or engineering, it's not necessarily that their structural allocation makes them bad, it is usually just that individual structures are themselves flawed.

(Though if anyone can find a liberal arts school that doesn't swell most of its students' heads to ridiculous degrees, I'd love to give them a grant or two)

[|333173|3|_||3]

But he does grudgingly admit that you can't really replace architects as if an engineer designed buildings, they'd all be rectangular blocks for ease of design, and not something that looks aesthetically pleasing.

Some of the buildings built around here are so ugly, a simple plain box would have been better. (see example below, it looks just as bad in real life). The new maths building at uni will be 8 stories of glass, with horizontal plates of glass outside the building between the floors, with no obvious means of access for cleaning. Furthermore, a lot of the pieces of glass will be coloured, in clashing pastels. Whilst it won't be the ugliest building, the architect who designed it could really have done better.

[Belial]

dude, those buildings *rock*.

[Hawknc]

Yeah, I actually don't mind that one...maybe it's because I'm from Melbourne, where until five or ten years ago every building in the city was a big grey brick, but at least it's interesting. I would probably have played around with the colours a little, though.

[Tomcat]

wellllll..... it is after all in the eye of the beholder. *Someone* is bound to like it. If all the buildings were blocks, then it would look like we were back in the USSR.

(Or govt housing structures in India )

[frezik]

I like the right side of that building (blue rounded bit), but the left just has far too many colors. Ditch a few and it'd be fine.

[Delbin]

My mom rants about lights all the time, and it drives me crazy for this reason.

But she does have a point, which is that light cycles around freeway on and off ramps always change in such a way that one is green and the next is red, making it hard to move forward. Can anyone out there explain why this is?

I remember watching a Scientific American Frontiers that had something about traffic. If you let everyone waiting go at once, it ends up causing traffic jams farther down the road. It's better to let people through in spurts in some situations.

Anyway, there's this light I use to take a left out of my work's parking lot. I often leave at 9:00 PM when the streets are mostly empty. I've gotten into the habit of reading a few pages out of my book when I'm waiting for the light. I've wondered if it's really necessary to wait that long when ther are so few cars on the road.

[Ender42081]

In my home town (freeport, IL... you have never heard of it unless you laughed at our team mascot) the downtown area has a long series of lights that seem like they are purposely set so 90% of the time you have to stop at each individual one. it is a one-way street so the fact that MAIN street does this is totally unreasonable.

I actually got out of a ticket once because, on my way to my fav coffee shop I used my trick of doing aprox. 38mph to defeat the timing. I was pulled over and was honest with him: "yeah, I deffinately was going over the speed limit, but it's the only way to get thru these lights and I take this road alot so I'm sick of them"... the police station is a few blocks away so he sympathized and let me go!!!

Turns out that some of my parent's friends who work for the city discovered that the lights are so old, that when they went thru to reset (fix) the timing every single light reset at midnight that day! they are currently tearing a bunch of them out and doing stop signs.

[Alcari]

Also, my town has what has to be one of the world's longest lights. (I timed it at over a minute.) It makes sense that it's so long given the traffic patterns there, but it's really annoying when you're on the wrong side of it.

A minute? There are 10 minutes traffic lights in Moscow, and I think it's hardly the longest possible time.

Yeah, but, having been to moscow, I must remark that they're almost as well followed as those in Amsterdam. "Traffic light? What traffic light?"

All traffic lights should have sensors during non-peak hours. Timing all lights all the time is stupid like a non-adaptive mesh. Even better, if the sensors realized whether the traffic was heavy and from which direction to set themselves to sensor or timed in whichever direction as necessary. Adaptive things make me soooo happy.

The modern traffic lights have an adaptive program, which gets closer to the "best timed" variant, as traffic on all streets increases. If only a few streets get heavy traffic, they're automatically giving more "green time" then the calm streets. In really calm hours they're usually set to All green for the main street.

Problems of this sort occur on multiple levels of the structure they exist in.

Of course, but it's always the fault of "He that earns more money by doing less work"

[4=5]

yeah, live action frogger

[Catswithcaptions]

Yeh, the worst light I ever sat through was right before I went for my 2nd Driver's License test. I was driving with my mom and sister, at the intersection of Broad and Packer in South Philly, and it was gridlock, gridlock, gridlock! There is a light right after the initial light, where I needed to make a left, and the green was not working, so you didn't know if you could go through, because only the red and one of the yellows were working. But the initial intersection, only one-way traffic was going straight across from Packer, and the first 3 lanes (or 2, I forget) were one way for Broad. Anyone who knows Broad Street, there's a lot of lights consecutively. You couldn't move without blocking the intersection, and being a young driver, I wasn't up to being cursed out by big burly Philly guys. After about 20 minutes, I decided to just gun it, and after another 10 minutes of blocking Broad Street, I made it across, a distance of about... 100 feet. Maybe not even that.

[snicker]

I'm a structural engineer in training (woo, graduating next may) and I live in Las Vegas. I've taken all the traffic engineering courses and I can definitely say that I empathize with this comic for sure!

Out of all the disciplines in civil engineering, transportation engineering is one of the most underrated (and in my opinion, most boring and easiest .

Here in Vegas though we have one of the first "intelligent" traffic control systems ever designed, and was deployed in 2003. Anyone interested can check it out here: http://www.rtcsouthernnevada.com/fast/. I have to say that it's very interesting even as someone who can't stand transportation engineering. I can't really imagine what traffic here would be like without it.

The way the system works is by analyzing traffic patterns through numerous means (CCD, microwave, magnetic sensors, manual data), it knows the traffic flow on all arterials during all times of day. I had one of the engineers who works for the system (ironically enough, it's called by the acronym... F.A.S.T.) explain to me how traffic was controlled on the various main arterials, say in peak morning traffic on week days. Most people are heading from the main residential areas on the outside parts of Vegas into the commercial and hotel districts in the center of the city. He explained to me that the lights are set to allow "bursts" of vehicles traveling within 3-4mph of the speed limit to catch a stream of green lights directly into the city... and I can attest to it, this system works almost flawlessly. This confirms the various theories that I've read from some of you that the average speed limit is enforced by engineers. In fact, the only way you can actually "beat" the cycle is to travel at 150% the speed limit (which I have done on some bad mornings) in order to ... catch up to the next burst of vehicles, and thus take about 2-3 minutes out of travel time. The system also has to calibrate these "bursts" so that the north-south traffic weaves perfectly with the east-west.

This isn't to say that we have a city completely devoid of traffic. It's still terrible during most typical rush hours, but it would be much worse without this. The Las Vegas Strip, where all the hotels and junk are... has been at capacity for over 10 years, and there's really no hope. If you head to Las Vegas Blvd on a friday or saturday evening between 4pm and 2am, it takes almost an hour to travel half a mile.

The other really nice thing is that all of the traffic flow information is available to anyone through a public FTP server, you just have to know the right people to ask to get a hold on the address. getting a couple pieces of data about typical light cycles on my main routes I was able to reduce travel times by up to 5 minutes in some cases by making a left and a right where i'd typically go straight and then left, or by leaving 2 minutes later and catching a different light cycle.

[sophomore]

(Though if anyone can find a liberal arts school that doesn't swell most of its students' heads to ridiculous degrees, I'd love to give them a grant or two)

I resent that. My head was already swollen.

[spacedman]

Out of all the disciplines in civil engineering, transportation engineering is one of the most underrated (and in my opinion, most boring and easiest .

Some editions of the UK Yellow Pages Phone Directory had the following entry:

Boring: see Civil Engineers

[tessuraea]

Wow, I feel really fortunate to live in Maine right now.

We do have plenty of traffic here (Portland, the largest city, heh), but *all* our lights have been replaced fairly recently and they make sense. At night, they all either go to blinking yellow on the main street and blinking red on the cross, or to simple sensor lights so the main streets stay green.

During the day, the busiest intersections are timed, the less busy ones use sensors, and I can only think of a few intersections I've been really annoyed by. I mean, there's one near my school that's a six-way one, where red lights last a while, but, well, it's a six-way intersection, so everyone has to wait a while for their turn.

I can think of a couple of spots where the lights are timed so that you can't hit them all green--but they're by schools and it was definitely deliberate.

I never realized that we were so lucky... maybe we just have really good traffic engineers.

[TLP]

This cartoon makes me look forward to finishing my training as a transportation engineer. What could be better than randomly hopping on cars and yelling at obnoxious complainers?

[DeadCatX2]

It would be a fun thing though, a searchable site where engineers can post up a 'why this is so' for various things. Most things would be stopped by patents held by their employer though, and other such non-disclosure business.

I think you're misunderstanding how patents work. All patents are publicly available...that's part of the whole patent thing.

Patents are a limited government monopoly on an invention, granted to encourage public disclosure of said invention for the good of the public, since you might not have otherwise disclosed the invention because you had no way to generate income from the invention.

Well...patents were that...once upon a time...now they're just a sword.

[KaneElson]

But he does grudgingly admit that you can't really replace architects as if an engineer designed buildings, they'd all be rectangular blocks for ease of design, and not something that looks aesthetically pleasing.

Some of the buildings built around here are so ugly, a simple plain box would have been better. (see example below, it looks just as bad in real life). The new maths building at uni will be 8 stories of glass, with horizontal plates of glass outside the building between the floors, with no obvious means of access for cleaning. Furthermore, a lot of the pieces of glass will be coloured, in clashing pastels. Whilst it won't be the ugliest building, the architect who designed it could really have done better.

I like the right side of that building (blue rounded bit), but the left just has far too many colors. Ditch a few and it'd be fine.

Just a little tidbit for the interested, that 'blue bit' is actually completely composed of sheets of oxidised copper. An insane cost for an effect that can't even be appreaciated from a distance. But it is a government building so what do you expect.