People will vote me down because the idea of a speeding self driving car sounds scary, but I personally can't wait until the software has advanced to the state that it can confidently drive 200 mph on the 5 from LA to the Bay Area. (Presumably they'd have to build a much bigger better 5, with special lanes dedicated to autonomous vehicles)

That is not how all speed limits are set; it just one possible technique: https://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa12004/

Or because they don't think that speed limits are set so that everyone can keep under them- but so that keeping under them means you're driving safely.

But you wouldn't expect a plane crash investigation to mention offhand that the flight computers were mildly overclocked.

A test drive of a new self-driving car should not speed, even if it's common or normal.

One car carefully observing a 30mph limit creates a hazard when everyone else is going 35-40.

Please be in the right lane if you are going slower than the flow of traffic. Regardless of whether or not you feel the people speeding are ultimately at fault, if everyone is speeding, it is a more dangerous to have a car that is going a dissimilar speed than it is for you to be speeding.

Keeping right is a small mitigating factor.

The first time you lose control of your car might be in icy conditions, and might be not just losing control, but spinning out of control in traffic. The line between in control and not in control can be very thin, and so hard to know how close you are to it.

By self-preservations instincts what I mean is that most people will try to be as safe as possible on the road, meaning drive slower on low-visibility situations, when there are many pedestrians around, etc. You cannot account on unforeseen circumstances or lack of knowledge, but otherwise people will try very hard not to get into harm's way.

As a fun thought experiment, imagine what would happen if your residential speed limit were raised from 25mph to 70mph. People may not hit the 70mph limit, but I can almost guarantee that the average speed would increase significantly, perhaps even dangerously in some cases. I don’t have much faith in people’s ability to judge space and speed accurately, particularly when they aren’t used to doing so. And this includes myself.

- https://www.citylab.com/design/2015/11/some-20-mph-streets-a...

- http://plannersweb.com/2013/09/wide-neighborhood-street-part...

> "Note that the people drive the speed they feel comfortable with regardless of the posted speed limit if enforcement is not present"

- ref: https://books.google.co.jp/books?id=tF7uyw7feOMC&pg=SA13-PA1...

And a paper:

- "PEOPLE DRIVE THE SPEED THEY ARE COMFORTABLE WITH ON GRAVEL ROADS REGARDLESS OF SPEED LIMIT, K-STATE RESEARCHERS SAY"

- https://www.k-state.edu/media/newsreleases/april09/speedlimi...

> Won’t raising the speed limit cause people to drive faster and cause more crashes?

> The Federal Highway Administration studied nearly 200 roads in 22 states where speed limits were raised, lowered or left unchanged. Prior to the speed limit change, 55 percent of drivers exceeded the posted speed limits. After speed limits were raised or lowered as much as 20 mph, there was a slight change in speed, but generally less than 1 mph. There were no significant changes in crashes, although crashes tended to decrease where speed limits were increased to realistic levels. Also, there was little effect on speeds or crashes on intersecting or nearby roadways.

So I guess I'm saying I agree. Speed limits are pretty arbitrary, there are a lot of things drivers do every day that are far more dangerous than merely speeding. Closure rate, unsafe passes, tailgating, cutting people off, etc.

/don't get me started about how people drive around you if you're towing a travel trailer, what the heck is it with people?

Then again under bad conditions on a 90km/h roads my survival instinct like you mentioned hasn't allowed me to go past 20-30km/h sometimes.

Imagine the car in front of you cycling rapidly between the gas and brake pedal to keep the speed exactly at 55mph. One, that’s completely impossible with how cars are designed, and two that’s really illogical. Cars have to follow the laws of physics too.

At town speeds I would expect it to use the brakes a lot more readily. At 30mph in 3rd (2000rpm) or 4th (1500rpm) there's not really all that much engine braking, and wind resistance won't slow it much either.

(Mine is a 2010 model, but I think this stuff was introduced in 2004-6, something like that... it's not exactly new technology.)

(Once or twice when going downhill without cruise control, just using the brake pedal, it "downshifted" automatically while I had the brake pedal pressed.

CVTs are computer controled and better than manual/standard for gas mileage, but with the downaide that you can't tow heavy loads.)

And the frustrating rubber-banding.

When it comes to accelerating and high RPM, I just don't mash the gas pedal down. By pressing the gas pedal on my car just enough, I can accelerate past other cars without high RPM just fine.

Gas pedal management is definately different with CVTs and other types of transmissions if you want a good driving experience.

It shouldn’t go over the speed limit, and under no circumstances should it take the liberty drivers usually take of being within 10% above the limit.

I hope no one wrote it that way.

Speed limits are usually too low. Often they have nothing to do with engineering or safety considerations, but are primarily revenue-oriented. If the advent of autonomous vehicles forces regulators to listen to the engineers for a change, that will be an unalloyed Good Thing.

-- 55% of drivers regularly exceed the speed limit, meaning that the speed limit represents the 45th percentile speed

-- driving between the 50th and 90th percentile speeds is the safest

Taken together, driving at the speed limit is significantly unsafe.

You have to remember that many people on here probably don't own a car, or necessarily even hold a driver's license. They most likely either live at home or at school, or take a bus to work (NTTAWWT).

Why not lower it to 5 MPH on a nationwide basis? Think of all the lives that would save!

Maybe they decided to change it.

The point of a self-driving car is unburdening the user from the task of driving it, allowing them to engage in other activities if they chose to do so.

That it has the potential of being safer is a nice perk but definitely not the primary goal. Right now the challenge is whether we can make them as safe on average as human drivers do, that way we can avoid effectively sacrificing people for the convenience such a system would provide.

That's a strange way to put it. Surely if someone is not driving their car, they can't be responsible if the car kills people (assuming of course the car was well-maintained and the model was legal). I don't see how that's a bad thing, since they have zero control over the situation.

Do you mean that it could make car users feel less responsible for deaths, even though cars will presumably still kill people?

If that's the case then I'm not sure how it is a benefit to society.

As with automatic escalators, there are two primary benefits to society: greater aggregate safety[1], and freeing up people's time. You point to the lack of a human operator to hold responsible as a detriment, but the statistics point the other way around: human drivers are horribly irresponsible and even if we can punish them when they do wrong that doesn't substantially change their behavior. Freeing up people's time is self-explanatory.

That's my point. I 100% agree, if self-driving cars did make things better, than the safety aspect is a good thing.

I think the freeing up people's time is okay too but only if all of society has access to AV's. However, like many innovations of the past, advancements which are not accessible to all people just free up the time of some people while offsetting burdens onto others (ie., those who can't afford AV's). BUT, that is a separate issue.

[0] It is just one data point, but it's a bad sign to be so quick to kill a pedestrian so soon out of the gate.

This kind of argument is just used to justify speeding.

LOL. I'm not sure if you're trolling, rude or just don't pay attention to the cars around you when you're driving, but I'll guess it's a combination of all 3.

>If you don't follow traffic flow, people will cut off in front of you, tailgate, zigzag, and do other dangerous lane changes/maneuvers much more frequently.

From my 45 years of observing people's driving and driving myself for about 30 years, I find that most people generally obey the speed limit or don't go much faster. Probably about 90% of people in general. At rush hour, it drops to about 50%. Some of the other 50% certainly do do all those fucked up, rude and dangerous things you mention, but it doesn't mean that the 50% of people obeying the speed limit are at fault. It's the impatient speeders who are at fault.

It's sometimes a bit of a Darwin award scenario. I live on Vancouver Island, and there is only a single highway over the mountains to Victoria. During commute times, about 50% of people speed significantly, and they do some of the dangerous and rude shit you mention. A few times a year one of them drives too fast for the conditions and ends up killing themselves, which then shuts down the entire north-south highway (the only fucking route) for 4 hours. The government is currently spending a shit ton of money to put barriers in the centre of the highway to try and prevent the excessively speeding idiots from killing themselves so often.

So no, I don't have much patience for the rude people who tailgate me, go 50km/h over the limit even in rain, and then get themselves killed and hold up the entire island for 4 hours because of their stupidity and lack of knowledge of basic physics.

(And I'm not calling out everyone who speeds, I do it myself sometimes, it's only the ones who go way over the limit with no consideration for weather conditions or safety, and the rude idiots who are in too much of a hurry to extend basic courtesy to other road users).

Regional culture definitely plays into this. I grew up in the midwest and almost everybody speeds. Now I live in Seattle and I'm the fast guy in the left lane going 5 MPH over the speed limit.

[1] It's not my problem if others get irate because I'm at the speed limit.

[2] It's not dangerous to be at the speed limit, it's dangerous to be over it. And you're not likely to hit someone going at the speed limit if you're dangerously speeding, you're likely to hit the median or an oncoming car, and more likely to get killed doing so (much greater speed differential than between the speeder and the person going at the speed limit).

[3] There is only a differential if you are passing, and that is easily managed by waiting for a sufficient gap in traffic.

It's not like in kindergarten where kids point at each other yelling it was the other who started it. If someone does something dangerous around me, it absolutely concerns my family's safety, regardless of what triggered the dangerous situation. Thinking two steps ahead to prevent these situations from occurring in the first place is at the core of defensive driving philosophy and it's why it's often recommended that one pick going with traffic flow instead of going at the posted speed limit if forced to choose given traffic conditions.

I agree that in many roads, going above the posted limit is a very accurate measure of recklessness, but that isn't the case everywhere and it isn't at all uncommon that the flow of traffic is 10 or even 20 km/h over the posted speed limit on many freeways or countryside roads.

Defensive driving means looking ahead and predicting when someone is going to do something stupid, not braking hard if someone is behind you, being very careful when changing lanes, driving in a parking lot, etc. It definitely doesn't mean driving above the speed limit to keep people behind you happy.

The law doesn't necessarily codify what's safe. You could go at 40km/h on a highway and be technically entirely within the law, but that's certainly not a safe thing to do. Similarly, you could go at exactly the posted speed limit on a snowstorm when everyone is driving slower and you would be entirely within the law, but you're probably going to get yourself killed.

Maybe if I always drive in the rightmost lane, being pedantic about posted limits is probably safe for a variety of reasons, but if I'm on the left lane of a 100km/h 3-lane highway, I wouldn't exactly feel comfortable going at 100 if everyone else is going at 125 (including cops).

How about when merging, or changing lanes? The speed limit is not _always_ safe or practical to obey strictly.

In the case of overtaking, you just need to make sure you don't cut someone off in the overtaking lane. No need to go over the speed limit just because you're too impatient to wait for a proper gap in the traffic.

I've never seen a situation where you're merging onto a freeway and everyone in the right-most lane is speeding excessively. That would be a very dangerous situation, and if you yourself go significantly faster than the speed limit to merge you're just adding to the dangerous problem.

https://travel.stackexchange.com/questions/40113/do-any-stat...

The way speedometers used to work is pretty interesting: http://www.explainthatstuff.com/how-speedometer-works.html

GPS is, as you said, wildly inaccurate, disconcertingly often. Wheelspeed is great when you're moving, but at low speed it tends not to have the granularity you want. Inertial sensors are pretty amazing nowadays, but they still drift.

To illustrate, if your wheels aren't moving, then you can ignore the IMU telling you that you're sinking into the ground at 5mm/s. Watching the monitor of a mapping vehicle as it depicts the car returning to mother Earth is pretty hysterical though. Until you have to fix it.