The game Error Prone is cute, but it mostly shows that it's very difficult to keep going a constant speed when your only controls are a binary "Full Throttle" and "Idle".
Which is exactly how some people drive - an ex- used to make me car sick with the way she drove - rather than maintaing a constant speed, she'd speed up 'till she got too close to the car in front of her (dangerously close), then let off on the gas (or even tap the brakes) to slow down.
Annoying and led to no end of arguments "Why are you always criticizing my driving!?".
With that style of driving, the minimum speed is also far more likely to drop to 0. And when one person is stopped, everyone behind them is stopped. Even for people who don't normally drive that way, add in a cell phone and that's exactly what starts to happen because they don't have enough remaining attention to avoid being "surprised" by a stopped car.
This is almost a perfect metaphor for the failings of capitalism, or at they very least the notion that the singular pursuit of selfish greed can lead to ideal outcomes. The selfish need for individual drivers to go as fast as they can leads to a collective failure, here in the form of a traffic jam.
It is fun to imagine how you could set up a price structure that incentivizes the right things to prevent traffic jams.
For example:
* A small per-second fee that is inversely related to the distance between your vehicle and the vehicle in front or behind you, whichever is closer. Maybe the distance scale would be dynamic based on speed, maybe measured in "estimated stopping time", such as (just as one wild example) a certain fee for being at 100% of safe estimated minimum stopping distance, a smaller one for 200%, a higher one for 50%, negligible or no fee for more than 1000%,
* A penalty fee for changing lanes. In dense or stop and go traffic, changing lanes imposes a pretty large cost on nearby traffic, as both lanes are stopped for a bit. Grass-is-greener temptation causes many drivers to change lanes, which quickly eliminates any sought advantage, but makes traffic worse as drivers essentially take up double space.
* etc?
Then dynamically tune the fees to get the desired result. Watch as frugal drivers economize by
* avoiding tailgating and unnecessary lane changing
* (because of the "minimum of distances" rule) learn to, in denser traffic, balance their available space between front and rear neighbors.
* are loathe to go too slow without making it easier for faster traffic to pass (if you want to enforce speed limits, maybe the distance-to-rear-neighbor cost should only be enforced when travelling below the speed limit?)
* Per-second instead of per-mile fees encourage drivers to avoid already jammed areas
As for hardware -- I guess the kind of hardware needed for adaptive cruise control / lane maintenance/merge assist now found on fancier vehicles is sufficient to measure and operate this (as long as few people successfully hack their toll measurement system, which I honestly think is realistic).
I agree, but I think traffic is really more of a classic "socialism vs. individualism" problem. Tragedy of the commons and all that. I think it's a little more zero-sum than many would have you believe that capitalism is, at least when there is any reasonable amount of traffic. The actions of greedy drivers can be felt for a long way, even if it may not seem like it in the moment.
Capitalists are generally smart enough to forego immediate gain in favor of substandard greater gains under different conditions.
Rather than drive as fast as I can in Atlanta's 8AM rush hour (and get nowhere fast in the ensuing jam), I leave for work before 6AM (with half the drive time).
You don't need "selfishness" to create traffic jams. You need only "latency in response"; if you response less than instantaneously to the car in front of you slowing down, and you response less than instantaneously to the car in front of you speeding up (especially if you accelerate even a bit conservatively, let alone late), you very quickly get amplifying waves.
Your post, if we're going to trade snarky political barbs, is a great example of how some people think that some magical form of "regulation" can regulate basic control theory right out of existence. Thinking that any form of regulation could somehow fix this is exactly the same as thinking that they could "fix" gravity. The physics is actually pretty simple at the core, even if the details are complicated. Anywhere you get negative feedback of a certain very, very popular and easy-to-hit form, you get waves. Can't be stopped.
You shouldn't even want to accelerate immediately at the same rate as the car in front of you, unless you're very optimistic about 1) having instant reflexes on the brake pedal even though your foot is currently on the gas pedal, and 2) your car's stopping distance being exactly the same as every other vehicle.
Having a time delay on your acceleration means that your following distance will increase as speed does, which is the safe behavior. I've had plenty of times when I thought "woo, we're accelerating, it's the end of the traffic jam!" and then had to hit the brakes when we came around a turn into more traffic. Traffic might be reduced if we all rode everyone's bumper all time time and accelerated as a single unit, but that doesn't mean we can actually do that without tons of collisions.
"You shouldn't even want to accelerate immediately at the same rate as the car in front of you,... but that doesn't mean we can actually do that without tons of collisions."
That is correct. Therefore, safe driving will actually create traffic waves. It seems unlikely we'd actually want the regulations that would prevent this sort of wave!
This game is easy to beat. Wreck most cars except a few, get a single car in the inner circle by slightly bumping it and press and hold the corresponding key.
Vehicles talking to each other will not break a practical traffic jam. The one caused because one car had to stop for some reason or other, now everyone has to stop or slow down in the same vicinity until there are less cars flowing through the area.
I'm not so sure. I think the big difference it would make to have cars talking to each other is that they can all know where the other (within a local range) is heading, make interchanges more optimal.
A lot of traffic congestion happens because we have nothing but (too-infrequently-used) turn signals to indicate our intentions. If all the cars knew where they were going at an interchange, you could at least optimize the flow.
Of course, there is _no_ solution when there are just too many cars trying to fit on a road that can't handle it. And that's probably 80-90% of the problem anyway :(
I have adaptive cruise control in my Subaru Legacy and I have often wondered what will happen when more people have ACC. Or even if I were following another car exactly like mine - would the lag time grow exponentially with more intense stop/go or would it even out? Or does it depend on how well the car implements it?
The adaptive cruise control in my Ford turns itself off if the speed is low enough-- which on Seattle-area freeways happens pretty often. So I stopped trying to use it.
The Subaru one stays on until you come to a complete stop. Even then, it's still "on" in a way, since it'll hold the brakes, but you have to flick up on the cruise control switch to get the car to start moving again. It'll also notify you if the car in front has started moving again and you haven't done anything (with or without ACC on). It's on my girlfriend's car, so I don't use it every day, but it has been nice the times I've driven it in traffic.
I used ACC on my mom's hybrid Accord recently and it was an aweful experience. It was like regular cruise control, but broken. Lagging start, unnecessary distances, slow responses. That and the out of lane beep whenever I passed a car (staying in the same lane but getting to the edge of the lane for increased margin of error) was really annoying. If this is the future of assisted driving, just give me fully automated driving.
This sort of traffic jam dissipation is only applicable to phantom traffic jams. Here in Los Angeles, traffic jams are caused by too many cars being on the road.
At some point, every available square foot of roadway is filled with a car. AI can help limit the amount of extra space taken up by air, but that will only moderately increase the number of cars that it will take before traffic hits. That number of cars will be reached, easily.
Not only that, AI will eliminate huge amounts of wasted road even during peak times and with traffic that can't be scheduled for off hours (like people going to work/school). A networked self-driving car can know where the traffic is and route around it. It can provide tools to everyone (from city planners to individuals) to maximize the availability of resources and minimize the time wasted on waiting. Red lights can cycle at the most efficient rate at all hours of the day, reversible lanes (like many large cities have on their primary highways) can be closed and opened on a dynamic schedule rather than on the preset schedule. When all cars are AI-driven and aware of all other cars, they can drive at exactly the right speed, allowing faster merges and exits, etc. Humans are wildly variable in their response time and unpredictable in their behavior in so many situations on the road, that replacing them seems likely to increase the capacity of roads by a dramatic amount. Maybe doubling? Maybe tripling? I don't know, but it will be a huge difference.
Theoretically, one doesn't even need directional lanes, anymore. You just have a road, and cars go where they most efficiently fit; lanes won't have any meaning anymore, just like most road signs won't have any purpose. If every car is communicating with every other car, and every car knows where it needs to go and how to get there in the shortest time, it can look like utter chaos to the human eye, and still be entirely safe (assuming we go to great lengths to insure reliable software and hardware).
Of course, I expect it to take decades for us to reach that point, which is really unfortunate. That's a lot of senseless auto collision deaths due to human error while we wait for the future to arrive. If governments were capable of looking forward, at all, they would recognize the massive savings an all AI road represents, both monetary and health, and would be pushing hard for it (both enabling private industry to implement it and guiding public funded research).
Increasing the efficiency of a process also tends to paradoxically increase its utilization (Jevon's Paradox). So it's entirely possible that automated trucking will actually increase total traffic volume.
Still though, even a few vehicles "eating traffic waves" can break up a traffic jam. I've heard the number put at 3-5% of traffic being self-driving would prevent phantom traffic jams.
So overall I would say that self-driving cars could help reduce phantom traffic jams, but they may actually increase real traffic jams caused by overcapacity.
Tariffs. If people want access to a congested zone, charge them for it. Dynamically adjust the tariff based on the level of congestion.
Of course people hate this and wail that it isn't fair, but it is among the more fair solutions to the immediate problem and inflicting traffic jams is probably not a good way to address economic inequality.
Agree. Tolls (assuming they means the same thing as tariffs) can also create the critical mass necessary for commuter bus lines to work, thereby allowing people to spend only a little more than they do now on commuting but get there faster since the roads are cleared. (The per person effective toll would be lower on a bus, even if they are charged by size.)
But they would have to be much higher than in most proposals, and they should be much lower or non-existence during hours when they're not choked despite the zero price.
Yes, toll is the better word. For a system with dynamic pricing, once you have a critical mass of vehicles with some sort of system to notify the drivers, you can even set the toll experimentally.
Tolls could even be done after the fact. Imagine a special tax on self-driving cars and trucks: 0.0x cents per mile if driven between 9AM and 5PM, based on mileage logs and all miles assumed to be driven then. If a corporation wants the discount, it can produce GPS logs showing its vehicles were logging all that mileage during off-peak hours.
So the poor person who needs to get to the doctor should take the slow lane, and the rich person who wants to get to the next bar faster should take the fast lane? Public utilities INTENTIONALLY are not and should not be run according to the principles of profit maximization.
The poor person should take the bus, which could actually be a fast option if the streets weren't choked at critical times. That's what a sane utility looks like. (If they're not choked, no congestion charge.)
I'm not a big fan of the mentality that the transportation system should suck just so we can avoid the rich have better options than the poor. Taken seriously, that would mean a ban on air travel because the poor can't have as much.
If you meant emergency vehicles, those always have priority :-p
Yea, I remember getting stuck in a huge traffic jam and feeling dumb for driving on 66 at rush hour. Until, I remembered it was Saturday. In northern VA traffic is often bad at from around 5AM to 10PM. But, we can have traffic jams at any time day or night 7 days a week.
Granted, bad night time traffic is often aided by construction. But, that does not help when your parked on a freeway at 3AM.
> At some point, every available square foot of roadway is filled with a car. AI can help limit the amount of extra space taken up by air, but that will only moderately increase the number of cars that it will take before traffic hits. That number of cars will be reached, easily.
The thing to keep in mind is that AI can limit the extra space between the cars as well as increase the speed those cars can safely travel. The cars will spend substantially less time on the road because they'll be going faster. Double the speed and you've converted a 60 minute commute into a 30 minute commute, doubling the number of commuters the roadway can support even if you don't adjust inter-car distance art all.
Don't forget Amdahl's law though. You might be able to optimize away the reaction time with good AI, but you can't optimize away mechanical factors like engine failure, tire grip, and road surface friction. This affects the maximum speed and traffic density just like a human's reaction time.
This means that if one car in a densely packed column fails (blowout, engine seizure, ...) then the car immediately behind it is still subject to its mechanical ability to avoid a collision (swerve into empty space or brake to a hard stop at speed) no matter how fast it reacts.
I often try the technique of leaving lots of space and going at a slower, steady pace. One problem is that everyone re-routes around you, and you induce road rage and traffic weaving. The other problem is that unless it's a straight stretch of road, you have no idea what speed is slow enough.
> They also seem to concentrate in the center lanes of the highway for reasons I haven't figured out yet.
Most likely because if a lane is closed it will be an edge lane. Also, if you're on a 3 lane road and two lanes are closed, you only have to make one lane change to keep going.
Not to mention that if the right lane is an "exit only" lane, merging a truck over a lane is pretty hard. No one wants to leave enough room. Or when you do leave enough room, some idiot sees that giant opening and moves into it.
In a traffic jam, wouldn't the alternative to leaving plenty of space be constantly starting and stopping? That seems pretty like a lot of work for the driver in a big rig.
ding ding ding ding! We have a winner. The just leave it in the fastest gear that is slow enough to not hit the car in front of them. For the extra 5min it costs it's a lot easier than pushing a bazillion pound clutch twice per cycle.
Yep! I've only ever driven manual transmission cars, and my dad taught me that early on. "Just leave it in first and idle along." Even in a very driver-friendly manual car, stop and go traffic can be brutal.
I cannot speak for others, but, at least to me, this reads as extremely condescending: it makes it sound like other commenters are basically picking arguments at random and you are the only one to know the truth.
Semi trucks aren't trying to calm traffic, they are maintaining a consistent speed (or rather engine RPM) and gear for fuel efficiency. Drivers are paid per mile and the further they can go on a single fill-up is more money in their pocket.
Edit to add: It is a computer telling them how fast to go, usually something similar to http://www.scangauge.com/
The other problem is that this isn't scalable. Imagine a traffic jam that stretches for miles. Now imagine that same jam where everyone has left an extra three car lengths in front of them. You're suddenly using a lot more road per car. Tailgating actually seems like the most efficient use of space to me, provided you tailgate effectively (don't yo-yo).
The jam might not necessarily occur in the first place if Everyone leaves three car lengths in front of them while in motion. Packing together at super slow or standstill traffic is okay. The goal is that traffic continues to flow at a reasonable pace; space between cars doesn't necessarily matter when determining how long it takes to get from point A to point B.
You're proposing changing the traffic pattern to look like a liquid instead of a gas. Guess which state has a higher viscosity?
If we all computerized cars that introduced 0 stochastic motion, this might work. But if one deer gets a dumb idea you're going to have a multi-kilometer pileup.
Not only is tailgating unsafe, but it's not possible to do it effectively. Even if you are a super-skilled racing driver, the driver ahead of you isn't, and he will slam on his brakes at the last second, forcing you to do the same, forcing the car behind you to do the same...rinse and repeat. Or you will hit him, or the car behind will hit you, etc, causing another accident and another traffic jam.
That's how the traffic jam happens in the first place. An accident happens, closing a lane, but the impatient people in that lane don't merge until the last second, forcing the people in the next lane to slow down quickly. Some people in the next lane don't leave room for cars to merge, forcing them to merge later, forcing them to do so at a slower speed, slowing down all the cars behind them in a cascading wave of brake lights.
What you're imagining might be possible with cooperative, AI-driven convoys of cars...until a black hat breaks in to their software over the Internet and makes them crash.[1]
What helps is to provide a buffer in your lane by moving at a consistent speed, avoiding braking altogether. Of course idiots are going to get mad and zoom around you once in a while, and that's fine, because they will clear space behind the wave, allowing traffic behind to move more smoothly.
The bottom line is that you can't control what other drivers do, and many drivers are stupid. You can control what you do, leaving more space, maintaining safe following distance, leaving room for cars to merge easily ahead of you, increasing your gas mileage by not braking, etc.
...or, according to what you say, being one of those idiots that are going to get made and zoom around once in a while.
Either way, this makes me think that a model where cars that are okay with driving slowly spreading around but leaving plenty of space in front of them. Similar to how (in California at least) motorcycles can filter filter though the traffic, cars that are impatient can use the large spacing between the slow moving cars to move forward.
> Probably a good indicator you are going too slow.
Which is okay, just please, please, PLEASE stay in the right lane.
Not necessarily. It dense, slow traffic, short-sighted drivers see open spaces; they rush for it, then slam on their brakes. It's amusing the frustration that this generates--for no real reason other than "I'm mad and going to tailgate you because you aren't tailgating the person in front of you".
If people swoop in front of me, Oh well. It's a pittance on my overall commute time, if effecting it at all. Generally it's just limited two a few very aggressive drivers, and I'd rather they tailgate the person in front of me rather than me.
A game I used to play with myself on the highway was to simply try and use my brakes as little as possible - when you see brake lights ahead it's instinctual to also brake yourself, but often if you have a long enough follow distance you can just lift off the gas.
Brake lights being a binary representation of an analogue pedal is another problem, although iirc on some newer cars the lights are brighter/more lights go on the harder you brake
IMO if you have to brake on the freeway, someone made an error.
Cool about brake lights; I've wondered for years why they don't do this. I knew about some newer cars flashing the hazard lights in a very hard stop, but didn't know any were doing brake light meters. Any idea which specific models? I'd love if they standardized the messaging across brands and countries; imagine a new mustang where 1 vertical bar on each side means light braking, 2 means moderate, and 3 + rapid flashing means very hard braking. Not sure what standard would make the most sense for this, but the sooner, the better, so new cars can adopt it. It's way less useful / less clear when each car does it differently.
I used to ride a motorcycle every day from the suburbs to Chicago's loop (until a crash on the way to work. heh) and I'm not sure that I'd want something like this. As binary as it initially seems, there's actually a lot more contextual information to it than you'd think. The swerviness, the length of the brake, how straight their car's going, how often they do it, head position, how in depth their conversations seem to be, etc. Like a lot of riders out there, I started playing mini games to try and figure out what the drivers were doing to help with determining risk. For me, imagining the physical position of their driving limbs, as weird as that may sound, was the most help. Thinking the problem in those terms helped out and really pushed the idea that if their foot is hovering over the brake, then a lot of caution is needed. I don't do this as much in a car, and I doubt many drivers do this, or anything close to it.
I think that if something like this was implemented, then a lot of people would use it as a crutch and make poor decisions based on implied safety eg, "His light didn't blink three times, so I didn't think to stop." That, and a lot of new cars, for some stupid reason, seem to want to obfuscate the significance of brake lights by just having them be brighter versions of on-by-default lights anyway or similar.
There definitely is something along those lines that'd be helpful, but I think it might have to be all or nothing there. Flooding phone frequencies with white noise might work, though ;)
I play this 'game' all the time, everywhere, and when it's time to slow down more than what simply releasing the pedal does I'll first try to shift down and have the engine brake for me. The latter not only because it lowers fuel usage but also because it makes me keep even more distance, which is the key point for me. It is just so much safer (hitting another car because you cannot brake in time isone of the most common accident types) and leads to much more relaxed driving without fast acceleration/deceleration. Only disadvantage so far: other drivers not understanding it and passing you in anger.
If you are shifting correctly that is not the case. The "breaking" is achieved by the engine, the wear on the transmission is the same as when you are stepping on the gas.
It also cause pressure waves in the exhaust system since you're using the vacuum forming in the engine to slow you down, which is more noticable at low rpms due to the slowing of the positive exhaust pressure changing to intake vacuum frequency. Going from acceleration to engine braking at low rpms, such as in traffic jams, has caused a weaken seam in my exhaust system to break.
Actually it's easier to manage speed and spacing in congestion with a gently curving stretch of road - cars further up are visible so you can anticipate better and slow down earlier/more gradually, reducing jerk. This way too, you won't seem slow to the people behind you. It's not so much going super slow as it is being able to correctly guess the average speed of the road and acting as a damper. This is basically what the article describes btw.
I also like to try and impose a rule of not touching the brakes unless absolutely necessary, and using 20% throttle input at most, that helps with the whole dampening thing.
One last caveat: these techniques only really work for freeways/highways in the developed world. The tragedy of the commons phenomenon is on a whole nother level in places like India or China (se asia in general) or a lot of Latin America or even sixth avenue.
> I also like to try and impose a rule of not touching the brakes unless absolutely necessary, and using 20% throttle input at most, that helps with the whole dampening thing.
I do the same. It's funny the frustration this seems to cause other people. Frustration from nothing, if they'd think about it.
"But I want to go fasterrrr! Why doesn't he goooooooo?!?!?" One time, a man and a lady in a Harley Davidson edition F150 got so mad at my for doing this that they were both screaming at me through my open sunroof, threatening to get out and physically assault me etc. They kept yelling at me to "learn how to drive". It as grid-lock traffic and we'd have minutes at a time of complete stoppage. That was a pretty awkward hour of my life.
Yeah I've had that a couple times. Once was a honk (I can only assume was) because I wasn't tailgating--yet we were moving at the same speed, so the driver swerved from behind me to the side and then in front--then slammed on their brakes.
The other time was after cruising during a lot of short stop and go intervals (so it was easy to judge crawling speed, that is to say). I eventually switched to the lane I needed and the guy who was rubberbanding behind me the entire way (pretty much going 1-10-1mph constantly instead of just sitting at 3 like me) pulled next to me and shook his head. I had a good feeling why, so I rolled down my window as we came to a stop next to each other at a light and asked if there was a problem. He said, "You drive like a dumb ass". "Oh, I do? Please tell me what I was doing wrong so I can improve". "You just drive like a dumbass". "No really, you seem like you know a lot about driving, please enlighten me". And he rolled up his window, the light turned green but he accelerated before the car in front of him had a chance to go (perhaps to get away from me, I'm 6'2" and 250lbs.), and then slammed on his brakes again...
Over here, I noticed it is much more pleasant to be stuck in rush hour traffic than off peak. At peak hour, people know the game and know they won't get anywhere faster by cutting and trying to fight for every inch. They tend to stay in their lane, merge smoothly and all lanes go the same speed.
But as soon as the traffic lightens a bit, idiots just come back to break the peace. I include myself in those.
Traffic jams exist because humans drive cars, and humans are not designed to process data at 120 kilometers per hour.
This is a major repost but still misses the main problem. When you look at a car in front of you, you perceive it as a stationary wall, not a moving wall. When you slow down, you're trying to avoid hitting where the car in front of you is when you press on the brake pedal. You're not smart enough to realize that you should be slowing down to avoid hitting where the car will be when that car stops.
You do this, and you should not be driving cars. Leaving space in front of you is an inefficient solution to this problem, now you're overcompensating even more for the problem.
You can try watching one car ahead of the one in front of you to predict when the car in front of you will slow down and need to stop. Your passengers will freak out, constantly thinking you're going to hit the car directly in front of you, because they perceive the car in front of you as a stationary wall. In reality, you're driving more efficiently.
The day when us unevolved meat sacks stop controlling two ton metal bullets can't come soon enough.
But my car weighs only 1600kg, and for years my passengers have been telling me I'm going to hit the car directly in front of me. Looks like that day has already come ;)
Traffic jams are often causes in the way the article suggests, and if you drive at the average speed, instead of the maximum legal or safe speed whenever you can, there's a good change the jam will have dissipated just before you reach it, and you'll get where you want to go just as fast.
This means that the cars behind you (provided it stays behind you) also don't have to stop. Their drivers should thank you for saving their fuel rather than curse you for driving too slow.
To minimize fuel consumption, it's best to drive in the highest gear, at the lowest speed for that gear. Failing that, to drive at a constant speed in the highest gear for that speed. If you do have to slow down, ease off the accelerator and change down gears, rather than use the brake. This means thinking ahead. You can do this when approaching a red traffic light, so that it will be green by the time you reach it.
There are a few other tricks to save fuel, such as driving at the minimum safe distance behind a big rig, and using gravity on hills to slow down or speed up.
This theory has been running around for a a few decades now. But a couple years ago I read a paper where they were studying traffic jams, and the conclusion is that elastic traffic is the problem, and this technique does nothing really to solve the problem. Instead simply maintaining the exact same spacing in front/back of your vehicle does a much better job of avoiding and clearing traffic jams.
When driving I've also noticed another phenomenon. When reaching the crest of a hill there's an optical illusion that cars are bunched together. From this viewpoint the driver can see more of the road and vehicles ahead. My theory is that this causes a momentary shock or panic, and it often causes drivers to slam on the brakes, causing ripples of braking behind them.
I wonder how much of this is mitigated by good lane discipline?
My SO actually got pulled over the other day (or at least that's what the cop used as an excuse) for driving in a passing lane when not passing anything. I said I was glad because it's a terrible habit - every lane ending up going the same speed as the slowest driver
TL;DR there is an effective maximum number of cars that can pass through a given point of roadway (about 1 car per 2 seconds per lane). No amount of space-leaving is going to chance that.
I think you need to read the update #2 in the page you linked, of course you can't create capacity out of nowhere, but if you are in a "phantom jam" situation it does help to "smooth things out" as the page clarifies (which I think is what this article is about)
That is the maximum number of cars that can pass a given point in 2 seconds; it does not mean that a road operating at peak capacity can reach that number.
You also have to take into account cars merging onto the road you are on. Imagine a road acting at peak efficiency, with a car passing every 2 seconds. Now merge in more cars. They are going to push back every car behind by that same 2 seconds.
You can read the section on 'merging' in the link above to read more details.
These roads, due to a complete lack of effective urban planning and development, are several times over capacity.
I like to think that this heuristic would be effective for such cases.
* Aim for a hard speed limit (maybe the actual speed limit).
* Actually obey the law of this state: Keep Right Except to Pass.
* ALWAYS allow merges (from either side) with higher priority.
Edit:
After reading the github link from one of the other posts I want to expand why I disagree and suggest always allowing merges.
It is to allow traffic to leave the freeway (merge right to exit) as well as to enter the freeway (merge left, mostly to enter at all, but also in case they're going a long distance or need to get to special use lanes on the left).
> Aim for a hard speed limit (maybe the actual speed limit).
That's not gonna work. Depends on the day, the time, the weather, rain, fog etc. Some days, traffic flows at 70 on 405 during rush hour. If you go the legal speed limit you will be the dangerous blockage that makes everyone else down, and makes a few people unnecessarily grumpy. Other days it's misty because the water on the road gets stirred up by all the trucks. It's impossible to go the speed limit on these days, the flow is going 45.
There is no hard rule, except: go with the flow. SEE the traffic. BE the traffic. Do not FIGHT the traffic.
Enforcing a speed limit on freeways is completely possible. They've got it done in England. What you need to do is capture license plates on entrance and exit, and calculate the average speed for each car's trip. If the speed limit is 50 MPH for traffic-flow reasons, and you do your 15 mile commute in 15 minutes, you're getting a "60 in a 50 MPH zone" ticket in the mail, every single time.
People will learn in a hurry that speeding is pretty much pointless and self-harming.
They've really got the surveillance state thing down to a science there, if they're doing things like that. In North America, where there are cameras, they tend to only look at your speed at a specific moment.
1) a lot of non-artery roads are really shitty in the UK
2) the UK is an island with lots of rivers and lakes so you may not have an option besides that particular road
3) UK average trips are likely much shorter
If they enforced speed limits on roads in the US with that technique, that road would simply stop being used. There are almost always other options, and the further you are traveling, the more options there are.
I want to propose a second more radical suggestion.
I think pacer cars might work very well for phantom traffic jams, but I very much disagree about /how/ they should be used. Instead of encouraging an over-capacity jam, I believe that the pacer cars should expressly communicate to other traffic something along the lines of.
"Temporary" / "Speed Limit" / "Follow at XX"
On a rear message board.
The pacer car would then draw out the stuck traffic in to the space /ahead/ of the jam and encourage the compression wave to expand to the front instead.
I just had fun crashing cars. 25 crashed with 1.8km travelled. I know it's not the point, but I don't care (nod to Icona Pop). I love it. I needed the laugh.
I would avoid blaming any traffic on "non-optimal" driving by other drivers (not leaving enough space so they maintain constant speed, stuff like that), since it's just another recipe for road rage.
I've always wanted to see what would happen if the government employed workers (maybe traffic cops) to take up each lane on the motorway, and form a line that you can't get passed, and drive at a speed just right to unclog traffic jams during peak hours.
I wonder how much more throughput and time saved we could get just by having lines of breakers every 50km or so on a highway during peak times.
A long long time ago, I stumbled onto the personal website of a guy who was really into this. He had little simulations of different types of traffic patterns, and how a single car could break it and return it to normal. It was really interesting, but I don't have the slightest idea on how to find that website again if it even still exists.
EDIT: Found in the comments, this may have been it. Honestly don't remember: http://trafficwaves.org/
This was one of the first sites I remember finding, in the late 90s. Back then it was hosted on the personal website provided by the author's dialup ISP, eskimo.com, as I recall.
Edit: I just noticed it still is hosted by eskimo.com, it just has its own domain now.
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