8 ms·

The weird, counter-intuitive science of traffic jams

63 points by Libertatea 13y ago

Shivetya 13y ago
I think the real revolution will be in long haul trucking, self driving trucks would go a long way towards increased delivery speed and safety. Throw in a standardized communications protocol and they could be tapped by a variety of services to relay real time traffic information, road conditions, and whatnot. They could be tossed into HOV lanes if isolation in city limits is preferred. As to the article, in Atlanta one major change that helped congestion was to implement throttled access via on ramps governed by lights. This tends to keep people from merging in groups which has a rubber band effect on existing traffic. Still more can be done by restricting areas of the highway to limit the lane changes. In Chicago I saw this done with bypass areas separated by cement walls. A simple solution but a bit cumbersome. Still separating some outside lanes would help.
- seanmcdirmid 13y ago
  Traffic on an entire urban freeway can be synchronized if automated, leading to huge bandwidth increases. In America, you might say whatever, but in china this will be transformative since there is nowhere else to build new roads...and the authoritarian government can easily deal with those who still want to drive themselves.
mrThe 13y ago
http://www.youtube.com/watch?v=r7_lwq3BfkY http://www.youtube.com/watch?v=r7_lwq3BfkY
sambeau 13y ago
The two main ways self-driving cars could clear up traffic jams are: * Far fewer cars needed — as more cars could be shared * Far fewer parked cars — as cars needn't stay with the 'driver' The two cases are linked: a car that doesn't have to wait around where the passengers are dropped off can return to base or can be away performing more lifts while the original passengers are busy. Families would have need for fewer vehicles. Sharing a vehicle would make more sense. If cars are busy during a drop-off-pick-up cycle there is no need for them to be clogging up the streets.
- dalore 13y ago
  Cue traffic jam of cars with no drivers because they are trying to get to their next passenger/base.
  - kps 13y ago
    A system could prioritize vehicles based on something like number of people per unit road surface.
  - sambeau 13y ago
    While there may be more cars doing return journeys I suspect there will not be the same level of traffic jams as the cars return. 1. Most outward trips would be chained: drop 1, drop 2, drop 3, return to base; rather than: drop 1, return to base, drop 2, return to base, drop 3, return to base. As would most return journeys. 2. The roads would be clearer in cities due to fewer parked cars. In some cases there would be an extra lane now available. 3. Cars could still have multiple bases, especially if they are shared. Car parks could be re-utilised as a stop-off points where empty cars could 'swap out' and remove themselves from the system briefly. 4. Chains could be linked: do the early run, do the late run. Do the Smiths; do the Joneses. 5. Empty cars with no urgent pick-up could wait for the roads to clear before embarking on a return journey. 6. Would anyone care if a car returns to base slowly if there wasn't an urgent passenger waiting? Cars could be more efficiently used and that would certainly imply that the fewer number of cars in existence would be being used for more trips throughout the day. I admit that it will be hard to remove the rush-hour problem entirely without a significant amount of car-sharing. However with a fully self-driving system cars could do clever passenger shares (and/or mid-route swaps). Passengers would be free to only car-share within their sex / family / workplace / social networks etc.
- noir_lord 13y ago
  There is also the option of owning a car but having it drive paying people around during the day while you are at the office amortizing the cost the car against it's utility. You'd get off a plane in a foreign city hit Web2point0nameforcarservice.com and a car would drive up (sending you a picture of the car and it's license to you and your details to the site (so we know who to bill if you throw up in the car for example)). This way you spread the cost of owning a car but it's available to you if you want to go away for the weekend (since you just mark it as out of service). It's going to be a wild ride (pun intended).
kps 13y ago
The article is fairly unimaginative. First, when most vehicles are self-driving, you no longer need traffic lights or lanes. An urban street that is currently 2+2 lanes could be used as 4+1 in the morning and 1+4 in the evening if that is what traffic requires. Second, self-driving vehicles remove a current disincentive to commuter microcars. A single person could easily get around in a car a third the size of a current subcompact if they didn't have to worry about being run over by land yachts. Beyond the lower cost, a half-lane vehicle could have a speed advantage in urban traffic.
- Zigurd 13y ago
  The article just mentions the perverse result that drivers drive closer to cyclists wearing helmets. That's just one aspect of how poorly most drivers drive near cyclists. Imagine being able to ride your bike in complete safety because the car behind you is literally incapable of running you over.
  - jellicle 13y ago
    You may not have paid much attention in physics class, but there is no possibility at all of having a situation where vehicles are both "literally incapable of running you over" and are travelling at a speed greater than 10mph or so.
    - gverri 13y ago
      That's not true. A self-driven car is made to anticipate decisions. Just like a normal human can stop if it sees something approaching. The difference is that the attention span, view range and response time of an AI is much superior than that of us. Of course it won't be 100% perfect. But just enough to make traffic some orders of magnitude safer.
  - ufmace 13y ago
    On the flip side, imagine what some cyclists will do if the cars are actually programmed to never run them over, no matter what they do. They would have to be given a pretty large 'bubble' around them with relatively slow traffic to really make sure of this, and then some cyclist will be a jerk and swerve all over the road erratically, throwing traffic into fits, just because he can do it safely. That's one of the trickier aspects of robo-cars that we'll have to figure out how to deal with when they start making up a significant amount of traffic. When humans are in control, there will always be a few people who are inclined to act like jerks as long as they can get away with it. On the roads today, the imperfect drivers around us and the prospect of a nasty crash tends to keep us all honest. What would the troublemakers do if the roads were 95%+ robo-cars that will drive such as to never hit them, no matter what they do?
Qantourisc 13y ago
A lot of traffic jams are the result of an improperly tuned car-accelerations and deceleration resulting in oscillations in the system. Learn people how to drive properly and keep their distance and things will be better. A good indication is on how much fuel you used in the traffic jam. (Electric car excluded). An auto-distance holder also helps to reduce the oscillation by 1 car, however correctly adjusting by hand is better. http://trafficwaves.org/ http://trafficwaves.org/
- seanmcdirmid 13y ago
  I'm guessing this only applies to America. Where I'm from, traffic jams result from ~150-200% over utilization rates. Accidents just make that worse.
  - Qantourisc 13y ago
    At my country it's also over-utilized, yet, you often see cars going slow, and then you do stop, for no reason, that can't be good for the little throughput you have left. It won't fix it then, but it should help.
    - seanmcdirmid 13y ago
      When your entire commute is stop and go, I don't see much hope in merely retraining the drivers. Self driving cars, on the other hand, can really optimize how limited capacity is utilized in developing countries like china (stuck in traffic right now in Beijing, which is way too normal here).
  - sambeau 13y ago
    The behaviour displayed in the video could easily have been from the UK. I suspect it applies to any large multi-lane highway / motorway / autobahn etc It was really interesting to see this as it demonstrates behaviour I've been experimenting with and have long wondered what difference it made. It's great to be vindicated!
- deleted 13y ago
  [deleted]
BasDirks 13y ago
"— We're all basically idiots when it comes to merging." We know.
jaynos 13y ago
Additionally, self driving cars would leave you free to read or surf the web during your commute. If you're relaxing and not driving, who cares if the commute takes a few more minutes...this would lead to a lot less lane changing, tail-gating, cutting people off, and many other causes of accidents and braking.
- hrkristian 13y ago
  This is my main point when discussing self-driving cars. Every minute spent on a commute is essentially time wasted, if I could do whatever I wanted while driving I wouldn't mind an hour long commute. The fact that we'd be distanced from the stress of driving, as you say, is also a great benefit, we're not really made for coping with the irritating nature of congested driving.
jheriko 13y ago
i was slightly stunned that this is not common sense: "experiments show that humans are really bad at judging the speed of an oncoming train at a crossing until it's nearly arrived" if you've ever seen this at e.g a train station even, is painfully obvious that your perception of this is terrible - trains in the distance look really slow. level crossings have been very common here in the uk for a long time... open crossings are the exception rather than the rule, and you have to go far out of your way to find them.
joshdance 13y ago
Can't wait for self driving cars. And the Hyperloop. And teleporters.
JonSkeptic 13y ago
My problem with self driving cars is not actually with self driving cars. I trust that our technology can reliably enable a vehicle to drive me around without my intervention. That's fine. There are two things I do not trust: I do not trust that our technology can successfully and intelligently respond in the event of an traffic or roadway anomaly, the kind that usually causes car crashes i.e. damaged roads, debris falling off of cars, erratic drivers, etc. Although I do trust safety features, which are pretty nice lately, I would rather have not have a wreck. Finally, I do not trust other drivers and I do not know how they will react/interact with a self driving car. It only takes one time for an idiot to flip out on the highway and cause a wreck. When I feel that the self driving can adequately handle anomalies, wrecks, and suicidally bad drivers, then I will have no qualms with the self driving car. Till then, I'm not willing to bet my life that it works well enough.
- hfsktr 13y ago
  I haven't done a lot of reading on self driving cars. No more than the occasional article on here. Do they have plans for cars that can operate in all weather conditions? I mean I never noticed if they ever said that the cars were only for mild weather areas. This was before I started thinking about the unknown variables that cause accidents: deer, a tire exploding, other debris (nails, glass, etc), some manufacturer or software bug. It's all too easy to imagine the software doing quite unexpected things when it gets to an unknown. Even if you could take control of the car I imagine most people wouldn't be paying attention to actually do it. This is just my panicky train of thought though. The tech is cool.
- mikeash 13y ago
  Let's not forget that all of the things you list are things that humans are pretty bad at. A self-driving car doesn't need to perfectly handle strange situations, it just needs to handle them better than most people, which is a much lower bar. Not saying we'll get there anytime soon, I don't know well enough to say. But I find that people in these discussions tend to overestimate the skill of most human drivers on the road.
- tghw 13y ago
  While the causes of road damage you cite are certainly more salient, they're not actually very common causes of accidents. Much more common is driver inattention or driver error. Inattention is directly addressed by self driving cars, as they are always paying attention. Error should be lower as well. As long as it can detect where another car is and it's approximate velocity, it should be able to avoid that car. Computers have far better reaction times than humans.
plg 13y ago
A large component of driving around in cars, at least for many, many people in north america, is not just for the purposes of transportation but simultaneously for displaying an expression of your personality. Many people buy particular cars because they view them as an expression of their personality (or an expression of their aspirations). Sure, this may be the "fault" of the car industry ... but whatever the origin, the fact is that it is the case today. What's more I think that the manner in which many people drive is also an expression of their personality. Sure, some people buy a toyota tercel and drive around in a machine-like state, purely for the purpose of transportation ... but I think the majority of people drive in a more "personalized" manner, for lack of a better term. I'm sure it's the case that google-self-driving-cars will be more efficient (and safer) transportation devices ... but the challenge will be that the masses will not easily migrate away from their personality-extensions (mustang, bmw, cadillac, convertible, truck, etc) into a pod-like utilitarian mode of transportation. No doubt, one reason why traffic is so inefficient is precisely because of these "personality" effects ... but there is much in life that is inefficient. In an age of google (and others) identifying the "inefficiencies" in our daily lives, we need to have a discussion about what features of our behaviour, and our daily lives, define us as individuals and make us human. Of course if part of your "personality" involves driving recklessly or putting people in danger, this is not a good state of affairs. But you get the gist of what I'm saying...
- redwood 13y ago
  On the other hand, the same could be said about the phone... A major personality device. Imagine the 80s exec on his office phone behind the leather desk. The power player in the early 90s in a "CAR phone". The suburbanite with the really long cord so he/she can use the phone anywhere in the living room/kitchen vicinity. etc. All of these were replaced by mobile phones which also become diversified as personality brands. The same will no doubt happen with self driven cars. So let's look for what the equivalent of the pickup, mustang, or prius will be in the self-driven era. My prediction: - Mustang will be fast looking, but self-driven. With a manual option (for driving on a track some place) - Pickup will be strong looking, but self-driven and with a manual mode expected to be used a lot - Prius will be small and utilitarian looking, without much expectation to be manually driven
bryanlarsen 13y ago
"people in convertibles are less likely to honk" I think that there should be a law that a car's horn should be as loud inside the car as it is outside. That's how loud it is for nearby cyclists & pedestrians -- drivers would be much more likely to use their horn only when it's really needed if it was as loud for them as it is for others.
- aroch 13y ago
  Go to India, you'll find that regardless of how loud the horn is to the person honking they're still going to use it
- ImprovedSilence 13y ago
  Meh, horns are a form of communication. Nobody honks a horn just for the hell of it. Sometimes you just gotta make others aware of the situation.
  - bryanlarsen 13y ago
    Of course they have a reason to honk. I just want it to be a good reason. My pet peeve is people who honk their horns rather than ring somebody's doorbell because they're too lazy to get out of their car.
tmuir 13y ago
Merging at the last possible moment _increases_ congestion. If there is a lane elimination, after the the lane has been eliminated, traffic speeds up, because there is no remaining merging to complete. Thus, the earlier merging is completed, the sooner traffic can recover from the disruption. Also, spreading out the merges over a longer distance, versus everyone merging in the same spot allows traffic to recover from many small distributed disruptions instead of one centralized large disruption. Early merging = less traffic.
- knowaveragejoe 13y ago
  I've seen this in action even on a pretty long merge segment for a lane reduction. It's a feedback loop of sorts, lots of people zoom up attempting to merge at the last possible moment and bypass the line of people that are slowing down because people further ahead were zooming up and trying to merge at the last possible moment.
- CanSpice 13y ago
  Do you have any proof for this, or is it just baseless conjecture? I suspect the latter, because nearly every link when you search for "traffic merging studies" states that late merging is more effective at reducing congestion. From the Minnesota DOT: "Minnesota DOT engineers developed what they call a "zipper," which meshes cars quickly. Signs advise drivers of the upcoming lane closure, tell them to use both lanes up to a point and then direct them to take turns merging. When traffic is flowing, drivers merge early to avoid unsafe maneuvers. But when traffic is congested, motorists make full use of both lanes. The data revealed that the change reduced traffic lines by 35 percent and also brought down "lane changing conflicts," says Craig Mittelstadt, Minnesota DOT's work zone safety specialist." From the Virginia DOT: "The late merge should be considered for 2-to-1 lane closure configurations to improve throughput when large numbers of heavy vehicles are present (>20 percent) for the majority of the time and congestion and queuing are often present."
  - saosebastiao 13y ago
    The Minnesota DOT website is widely cited by proponents of the zipper merge as a way of reducing congestion. However, it makes no claims about increasing throughput...it is about maximizing road space utilization. Early merges occupy more space, but the benefits to this space utilization are ancillary to the throughput congestion: fewer cross streets or exits are blocked by people not intending to use them. The question of lane change conflicts is not exactly clear...what is a conflict? When someone doesn't want to let you in? If so, that is a question of human behavior, not the physics of the situation. The Virginia site recommends late merges for when >20% of the vehicles are heavy vehicles, which is due to their merging complications (maybe something to do with those pesky "lane change conflicts"). It is obviously not a general recommendation. There is no clear data for either position on throughput...because ultimately throughput is limited by the bottleneck, which is the lane closure, not the merge behavior. People who spend too much time in their cars tend to be religious about the appropriateness of certain driving behaviors, and like any faith-based conviction, will tend to over-extrapolate empirical evidence to their context of choice.
twoodfin 13y ago
One study that tracked drivers in Boston during rush hour found that if you could remove just 1 percent of people on the road (say, to mass transit), you could achieve a whopping 18 percent improvement in traffic flow. But for whatever reason, cities haven't figured out how to do that just yet. If you don't think in static terms, this is obvious. Across any segment of time, some fraction of commuters will change their habits based on their expectations of time/cost/comfort. Some commuters can respond daily if, for example, they have a car and affordable parking at their destination as well as access to public transit. Other commuters may not have a car at all but will eventually buy one if it begins to offer substantial advantages over its cost. The point is that the system is dynamic. And if, magically, the City of Boston could wave a wand and redirect 1% of its commuters to the subway, they'd soon discover that the 18% improvement in traffic flow has tempted many other commuters back onto the roads, and the benefit vanishes.
- markbernard 13y ago
  People don't want to move to mass transit because it sucks. During rush hour it only takes me 25 minutes to drive to work. If I took the bus it takes 2 hours. You will never get me to give up my car with times like that.
jonnathanson 13y ago
An interesting corollary: removing traffic lights in busy intersections might reduce accidents and improve traffic flow. Some small pilot studies have been carried out in Europe, often with successful results. Basically, the idea is that we become more alert when a situation requires us to be. An intersection that appears riskier forces us to give it more conscious and subconscious attention. http://knowledge.allianz.com/mobility/transportation_safety/?1841/risker-streets-reduce-accidents http://knowledge.allianz.com/mobility/transportation_safety/... Anecdotally, I can certainly testify to the effects of traffic lights on traffic. I grew up and worked for a lot of my life in LA, a city as famous for its traffic as for its movies and weather. There are certain parts of the city in which every damned block has a traffic light, and blocks are very short in the denser areas. These areas are traffic hellholes. Beverly Hills in rush hour would have made a cameo appearance in Dante's Inferno, had he been around to experience it.
- pak 13y ago
  Too many unsynched traffic lights in a grid formation often results in you sitting at a red light with no traffic moving in front of you, which is infuriating and inefficient. (Case in point, besides LA, is Toronto which seems to be designed this way on purpose.) This situation is alleviated by stop signs or traffic circles that give you the ability to advance when there is, in fact, no cross traffic.
mathattack 13y ago
— Cars tend to drive closer to bicyclists who are wearing helmets. That comes from Ian Walker, who set up a bicycle with sensors and drove around the city. Vehicles tend to crowd closer to him when he was wearing a helmet than when he wasn't. That's not necessarily surprising, but it's a reminder of all the weird unconscious tics we adopt while driving and making on-the-fly assumptions. This is a weird adaptation of the Peltzman effect[1], which found that people drove more recklessly when wearing seatbelts. [1] http://gregmankiw.blogspot.com/2006/07/peltzman-effect.html http://gregmankiw.blogspot.com/2006/07/peltzman-effect.html

63 points by Libertatea 13y ago

I think the real revolution will be in long haul trucking, self driving trucks would go a long way towards increased delivery speed and safety. Throw in a standardized communications protocol and they could be tapped by a variety of services to relay real time traffic information, road conditions, and whatnot. They could be tossed into HOV lanes if isolation in city limits is preferred. As to the article, in Atlanta one major change that helped congestion was to implement throttled access via on ramps governed by lights. This tends to keep people from merging in groups which has a rubber band effect on existing traffic. Still more can be done by restricting areas of the highway to limit the lane changes. In Chicago I saw this done with bypass areas separated by cement walls. A simple solution but a bit cumbersome. Still separating some outside lanes would help.

seanmcdirmid 13y ago
Traffic on an entire urban freeway can be synchronized if automated, leading to huge bandwidth increases. In America, you might say whatever, but in china this will be transformative since there is nowhere else to build new roads...and the authoritarian government can easily deal with those who still want to drive themselves.

mrThe 13y ago

http://www.youtube.com/watch?v=r7_lwq3BfkY http://www.youtube.com/watch?v=r7_lwq3BfkY

sambeau 13y ago

The two main ways self-driving cars could clear up traffic jams are: * Far fewer cars needed — as more cars could be shared * Far fewer parked cars — as cars needn't stay with the 'driver' The two cases are linked: a car that doesn't have to wait around where the passengers are dropped off can return to base or can be away performing more lifts while the original passengers are busy. Families would have need for fewer vehicles. Sharing a vehicle would make more sense. If cars are busy during a drop-off-pick-up cycle there is no need for them to be clogging up the streets.

dalore 13y ago
Cue traffic jam of cars with no drivers because they are trying to get to their next passenger/base.
- kps 13y ago
  A system could prioritize vehicles based on something like number of people per unit road surface.
- sambeau 13y ago
  While there may be more cars doing return journeys I suspect there will not be the same level of traffic jams as the cars return. 1. Most outward trips would be chained: drop 1, drop 2, drop 3, return to base; rather than: drop 1, return to base, drop 2, return to base, drop 3, return to base. As would most return journeys. 2. The roads would be clearer in cities due to fewer parked cars. In some cases there would be an extra lane now available. 3. Cars could still have multiple bases, especially if they are shared. Car parks could be re-utilised as a stop-off points where empty cars could 'swap out' and remove themselves from the system briefly. 4. Chains could be linked: do the early run, do the late run. Do the Smiths; do the Joneses. 5. Empty cars with no urgent pick-up could wait for the roads to clear before embarking on a return journey. 6. Would anyone care if a car returns to base slowly if there wasn't an urgent passenger waiting? Cars could be more efficiently used and that would certainly imply that the fewer number of cars in existence would be being used for more trips throughout the day. I admit that it will be hard to remove the rush-hour problem entirely without a significant amount of car-sharing. However with a fully self-driving system cars could do clever passenger shares (and/or mid-route swaps). Passengers would be free to only car-share within their sex / family / workplace / social networks etc.
noir_lord 13y ago
There is also the option of owning a car but having it drive paying people around during the day while you are at the office amortizing the cost the car against it's utility. You'd get off a plane in a foreign city hit Web2point0nameforcarservice.com and a car would drive up (sending you a picture of the car and it's license to you and your details to the site (so we know who to bill if you throw up in the car for example)). This way you spread the cost of owning a car but it's available to you if you want to go away for the weekend (since you just mark it as out of service). It's going to be a wild ride (pun intended).

kps 13y ago

The article is fairly unimaginative. First, when most vehicles are self-driving, you no longer need traffic lights or lanes. An urban street that is currently 2+2 lanes could be used as 4+1 in the morning and 1+4 in the evening if that is what traffic requires. Second, self-driving vehicles remove a current disincentive to commuter microcars. A single person could easily get around in a car a third the size of a current subcompact if they didn't have to worry about being run over by land yachts. Beyond the lower cost, a half-lane vehicle could have a speed advantage in urban traffic.

Zigurd 13y ago
The article just mentions the perverse result that drivers drive closer to cyclists wearing helmets. That's just one aspect of how poorly most drivers drive near cyclists. Imagine being able to ride your bike in complete safety because the car behind you is literally incapable of running you over.
- jellicle 13y ago
  You may not have paid much attention in physics class, but there is no possibility at all of having a situation where vehicles are both "literally incapable of running you over" and are travelling at a speed greater than 10mph or so.
  - gverri 13y ago
    That's not true. A self-driven car is made to anticipate decisions. Just like a normal human can stop if it sees something approaching. The difference is that the attention span, view range and response time of an AI is much superior than that of us. Of course it won't be 100% perfect. But just enough to make traffic some orders of magnitude safer.
- ufmace 13y ago
  On the flip side, imagine what some cyclists will do if the cars are actually programmed to never run them over, no matter what they do. They would have to be given a pretty large 'bubble' around them with relatively slow traffic to really make sure of this, and then some cyclist will be a jerk and swerve all over the road erratically, throwing traffic into fits, just because he can do it safely. That's one of the trickier aspects of robo-cars that we'll have to figure out how to deal with when they start making up a significant amount of traffic. When humans are in control, there will always be a few people who are inclined to act like jerks as long as they can get away with it. On the roads today, the imperfect drivers around us and the prospect of a nasty crash tends to keep us all honest. What would the troublemakers do if the roads were 95%+ robo-cars that will drive such as to never hit them, no matter what they do?

Qantourisc 13y ago

A lot of traffic jams are the result of an improperly tuned car-accelerations and deceleration resulting in oscillations in the system. Learn people how to drive properly and keep their distance and things will be better. A good indication is on how much fuel you used in the traffic jam. (Electric car excluded). An auto-distance holder also helps to reduce the oscillation by 1 car, however correctly adjusting by hand is better. http://trafficwaves.org/ http://trafficwaves.org/

seanmcdirmid 13y ago
I'm guessing this only applies to America. Where I'm from, traffic jams result from ~150-200% over utilization rates. Accidents just make that worse.
- Qantourisc 13y ago
  At my country it's also over-utilized, yet, you often see cars going slow, and then you do stop, for no reason, that can't be good for the little throughput you have left. It won't fix it then, but it should help.
  - seanmcdirmid 13y ago
    When your entire commute is stop and go, I don't see much hope in merely retraining the drivers. Self driving cars, on the other hand, can really optimize how limited capacity is utilized in developing countries like china (stuck in traffic right now in Beijing, which is way too normal here).
- sambeau 13y ago
  The behaviour displayed in the video could easily have been from the UK. I suspect it applies to any large multi-lane highway / motorway / autobahn etc It was really interesting to see this as it demonstrates behaviour I've been experimenting with and have long wondered what difference it made. It's great to be vindicated!
deleted 13y ago
[deleted]

BasDirks 13y ago

"— We're all basically idiots when it comes to merging." We know.

jaynos 13y ago

Additionally, self driving cars would leave you free to read or surf the web during your commute. If you're relaxing and not driving, who cares if the commute takes a few more minutes...this would lead to a lot less lane changing, tail-gating, cutting people off, and many other causes of accidents and braking.

hrkristian 13y ago
This is my main point when discussing self-driving cars. Every minute spent on a commute is essentially time wasted, if I could do whatever I wanted while driving I wouldn't mind an hour long commute. The fact that we'd be distanced from the stress of driving, as you say, is also a great benefit, we're not really made for coping with the irritating nature of congested driving.

jheriko 13y ago

i was slightly stunned that this is not common sense: "experiments show that humans are really bad at judging the speed of an oncoming train at a crossing until it's nearly arrived" if you've ever seen this at e.g a train station even, is painfully obvious that your perception of this is terrible - trains in the distance look really slow. level crossings have been very common here in the uk for a long time... open crossings are the exception rather than the rule, and you have to go far out of your way to find them.

joshdance 13y ago

Can't wait for self driving cars. And the Hyperloop. And teleporters.

JonSkeptic 13y ago

My problem with self driving cars is not actually with self driving cars. I trust that our technology can reliably enable a vehicle to drive me around without my intervention. That's fine. There are two things I do not trust: I do not trust that our technology can successfully and intelligently respond in the event of an traffic or roadway anomaly, the kind that usually causes car crashes i.e. damaged roads, debris falling off of cars, erratic drivers, etc. Although I do trust safety features, which are pretty nice lately, I would rather have not have a wreck. Finally, I do not trust other drivers and I do not know how they will react/interact with a self driving car. It only takes one time for an idiot to flip out on the highway and cause a wreck. When I feel that the self driving can adequately handle anomalies, wrecks, and suicidally bad drivers, then I will have no qualms with the self driving car. Till then, I'm not willing to bet my life that it works well enough.

hfsktr 13y ago
I haven't done a lot of reading on self driving cars. No more than the occasional article on here. Do they have plans for cars that can operate in all weather conditions? I mean I never noticed if they ever said that the cars were only for mild weather areas. This was before I started thinking about the unknown variables that cause accidents: deer, a tire exploding, other debris (nails, glass, etc), some manufacturer or software bug. It's all too easy to imagine the software doing quite unexpected things when it gets to an unknown. Even if you could take control of the car I imagine most people wouldn't be paying attention to actually do it. This is just my panicky train of thought though. The tech is cool.
mikeash 13y ago
Let's not forget that all of the things you list are things that humans are pretty bad at. A self-driving car doesn't need to perfectly handle strange situations, it just needs to handle them better than most people, which is a much lower bar. Not saying we'll get there anytime soon, I don't know well enough to say. But I find that people in these discussions tend to overestimate the skill of most human drivers on the road.
tghw 13y ago
While the causes of road damage you cite are certainly more salient, they're not actually very common causes of accidents. Much more common is driver inattention or driver error. Inattention is directly addressed by self driving cars, as they are always paying attention. Error should be lower as well. As long as it can detect where another car is and it's approximate velocity, it should be able to avoid that car. Computers have far better reaction times than humans.

plg 13y ago

A large component of driving around in cars, at least for many, many people in north america, is not just for the purposes of transportation but simultaneously for displaying an expression of your personality. Many people buy particular cars because they view them as an expression of their personality (or an expression of their aspirations). Sure, this may be the "fault" of the car industry ... but whatever the origin, the fact is that it is the case today. What's more I think that the manner in which many people drive is also an expression of their personality. Sure, some people buy a toyota tercel and drive around in a machine-like state, purely for the purpose of transportation ... but I think the majority of people drive in a more "personalized" manner, for lack of a better term. I'm sure it's the case that google-self-driving-cars will be more efficient (and safer) transportation devices ... but the challenge will be that the masses will not easily migrate away from their personality-extensions (mustang, bmw, cadillac, convertible, truck, etc) into a pod-like utilitarian mode of transportation. No doubt, one reason why traffic is so inefficient is precisely because of these "personality" effects ... but there is much in life that is inefficient. In an age of google (and others) identifying the "inefficiencies" in our daily lives, we need to have a discussion about what features of our behaviour, and our daily lives, define us as individuals and make us human. Of course if part of your "personality" involves driving recklessly or putting people in danger, this is not a good state of affairs. But you get the gist of what I'm saying...

redwood 13y ago
On the other hand, the same could be said about the phone... A major personality device. Imagine the 80s exec on his office phone behind the leather desk. The power player in the early 90s in a "CAR phone". The suburbanite with the really long cord so he/she can use the phone anywhere in the living room/kitchen vicinity. etc. All of these were replaced by mobile phones which also become diversified as personality brands. The same will no doubt happen with self driven cars. So let's look for what the equivalent of the pickup, mustang, or prius will be in the self-driven era. My prediction: - Mustang will be fast looking, but self-driven. With a manual option (for driving on a track some place) - Pickup will be strong looking, but self-driven and with a manual mode expected to be used a lot - Prius will be small and utilitarian looking, without much expectation to be manually driven

bryanlarsen 13y ago

"people in convertibles are less likely to honk" I think that there should be a law that a car's horn should be as loud inside the car as it is outside. That's how loud it is for nearby cyclists & pedestrians -- drivers would be much more likely to use their horn only when it's really needed if it was as loud for them as it is for others.

aroch 13y ago
Go to India, you'll find that regardless of how loud the horn is to the person honking they're still going to use it
ImprovedSilence 13y ago
Meh, horns are a form of communication. Nobody honks a horn just for the hell of it. Sometimes you just gotta make others aware of the situation.
- bryanlarsen 13y ago
  Of course they have a reason to honk. I just want it to be a good reason. My pet peeve is people who honk their horns rather than ring somebody's doorbell because they're too lazy to get out of their car.

tmuir 13y ago

Merging at the last possible moment _increases_ congestion. If there is a lane elimination, after the the lane has been eliminated, traffic speeds up, because there is no remaining merging to complete. Thus, the earlier merging is completed, the sooner traffic can recover from the disruption. Also, spreading out the merges over a longer distance, versus everyone merging in the same spot allows traffic to recover from many small distributed disruptions instead of one centralized large disruption. Early merging = less traffic.

knowaveragejoe 13y ago
I've seen this in action even on a pretty long merge segment for a lane reduction. It's a feedback loop of sorts, lots of people zoom up attempting to merge at the last possible moment and bypass the line of people that are slowing down because people further ahead were zooming up and trying to merge at the last possible moment.
CanSpice 13y ago
Do you have any proof for this, or is it just baseless conjecture? I suspect the latter, because nearly every link when you search for "traffic merging studies" states that late merging is more effective at reducing congestion. From the Minnesota DOT: "Minnesota DOT engineers developed what they call a "zipper," which meshes cars quickly. Signs advise drivers of the upcoming lane closure, tell them to use both lanes up to a point and then direct them to take turns merging. When traffic is flowing, drivers merge early to avoid unsafe maneuvers. But when traffic is congested, motorists make full use of both lanes. The data revealed that the change reduced traffic lines by 35 percent and also brought down "lane changing conflicts," says Craig Mittelstadt, Minnesota DOT's work zone safety specialist." From the Virginia DOT: "The late merge should be considered for 2-to-1 lane closure configurations to improve throughput when large numbers of heavy vehicles are present (>20 percent) for the majority of the time and congestion and queuing are often present."
- saosebastiao 13y ago
  The Minnesota DOT website is widely cited by proponents of the zipper merge as a way of reducing congestion. However, it makes no claims about increasing throughput...it is about maximizing road space utilization. Early merges occupy more space, but the benefits to this space utilization are ancillary to the throughput congestion: fewer cross streets or exits are blocked by people not intending to use them. The question of lane change conflicts is not exactly clear...what is a conflict? When someone doesn't want to let you in? If so, that is a question of human behavior, not the physics of the situation. The Virginia site recommends late merges for when >20% of the vehicles are heavy vehicles, which is due to their merging complications (maybe something to do with those pesky "lane change conflicts"). It is obviously not a general recommendation. There is no clear data for either position on throughput...because ultimately throughput is limited by the bottleneck, which is the lane closure, not the merge behavior. People who spend too much time in their cars tend to be religious about the appropriateness of certain driving behaviors, and like any faith-based conviction, will tend to over-extrapolate empirical evidence to their context of choice.

twoodfin 13y ago

One study that tracked drivers in Boston during rush hour found that if you could remove just 1 percent of people on the road (say, to mass transit), you could achieve a whopping 18 percent improvement in traffic flow. But for whatever reason, cities haven't figured out how to do that just yet. If you don't think in static terms, this is obvious. Across any segment of time, some fraction of commuters will change their habits based on their expectations of time/cost/comfort. Some commuters can respond daily if, for example, they have a car and affordable parking at their destination as well as access to public transit. Other commuters may not have a car at all but will eventually buy one if it begins to offer substantial advantages over its cost. The point is that the system is dynamic. And if, magically, the City of Boston could wave a wand and redirect 1% of its commuters to the subway, they'd soon discover that the 18% improvement in traffic flow has tempted many other commuters back onto the roads, and the benefit vanishes.

markbernard 13y ago
People don't want to move to mass transit because it sucks. During rush hour it only takes me 25 minutes to drive to work. If I took the bus it takes 2 hours. You will never get me to give up my car with times like that.

jonnathanson 13y ago

An interesting corollary: removing traffic lights in busy intersections might reduce accidents and improve traffic flow. Some small pilot studies have been carried out in Europe, often with successful results. Basically, the idea is that we become more alert when a situation requires us to be. An intersection that appears riskier forces us to give it more conscious and subconscious attention. http://knowledge.allianz.com/mobility/transportation_safety/?1841/risker-streets-reduce-accidents http://knowledge.allianz.com/mobility/transportation_safety/... Anecdotally, I can certainly testify to the effects of traffic lights on traffic. I grew up and worked for a lot of my life in LA, a city as famous for its traffic as for its movies and weather. There are certain parts of the city in which every damned block has a traffic light, and blocks are very short in the denser areas. These areas are traffic hellholes. Beverly Hills in rush hour would have made a cameo appearance in Dante's Inferno, had he been around to experience it.

pak 13y ago
Too many unsynched traffic lights in a grid formation often results in you sitting at a red light with no traffic moving in front of you, which is infuriating and inefficient. (Case in point, besides LA, is Toronto which seems to be designed this way on purpose.) This situation is alleviated by stop signs or traffic circles that give you the ability to advance when there is, in fact, no cross traffic.

mathattack 13y ago

— Cars tend to drive closer to bicyclists who are wearing helmets. That comes from Ian Walker, who set up a bicycle with sensors and drove around the city. Vehicles tend to crowd closer to him when he was wearing a helmet than when he wasn't. That's not necessarily surprising, but it's a reminder of all the weird unconscious tics we adopt while driving and making on-the-fly assumptions. This is a weird adaptation of the Peltzman effect[1], which found that people drove more recklessly when wearing seatbelts. [1] http://gregmankiw.blogspot.com/2006/07/peltzman-effect.html http://gregmankiw.blogspot.com/2006/07/peltzman-effect.html