Not double. The computers would probably have good enough reaction times to allow that, but that’s not the only limiting factor. At that kind of speed, fuel economy is going to be in the toilet, and while a few owners won’t mind that, most will, so you’d need either lanes for different speeds, or the whole road slower, to accommodate that. 130 MPH probably isn’t safe for the tires, either: High speed increases both the risk and the consequences of a blowout.
It will be hard for a cop to come up with a probable cause to stop a self-driving car 
if it’s incorporated into the map/guidance data I don’t see it as a big concern. the built-in nav systems in many cars already have the speed limits for most roads (if you have the compass or nav display on the gauge cluster on Ford vehicles, it’ll also display the current speed limit.) since autonomous cars will likely have to be connected, this information could be acquired/sent to the car in real time.
There are already enough distractions on the road, like too many signs, now you’re going to have all of these distracted drivers driving around in cars with HUD displays and alerts telling them that they’re too close to a line and whatever, I think it’s going to make driving more distracted.
The drivers won’t be paying attention to the HUDs and alerts. The drivers will be producing the HUDs and alerts, to keep the passengers informed.
I’ll bet you a nickel that your sat nav does not show the speed limit as 25 in a school zone during the few hours a day when it is 25.
I will bet you a dollar that it doesn’t show the speed limit change on “weird” days, like half days when school lets out early.
My point was: if the school zone change is always at the same time of day and on predictable days, that is data the cars can be given. If the time is variable, that is more likely to be something the cars will need to figure out for themselves, just like the humans.
Doable, but harder.
Tesla already has this in production models.
Google cars are already aware of nearby pedestrians, school zones with pedestrian presence can default to “school zone” no matter what time of day it is. computers are plenty capable of logical steps creating a variety of end results. A car may not recognize hand gestures but it will stop for a crossing guard or police officer obstructing a lane.
Actually tractor trailers that spend the vast majority of their time on the freeway would benefit immensely from unloading some portion of the driving responsibility to computers.
Perhaps. I don’t know what the demand is like for truck drivers, but every school district in my state is now hiring in desperate need of bus drivers.
Both vocations are potentially amenible to being augmented and eventually replaced by autonomous pilots, but the problem with autonomous school buses is one of perception; parents are going to have to believe that the buses are absolutely safe before they’ll accept them, and any accident whatsoever will undermine that perception whether is is a genuine vulnerability. On the other hand, municipal and long route buses have an essentially captive audience (people who are forced to use public transportation, or who cannot fly) and so would be an ideal candidate for application.
Long haul and distribution hub trucking is a good application, too; not only would reliable autonomous trucks be safer and more efficient, but given that they’d be able to operate around the clock without break (other than fuel and maintenance) means you’d see significant increase in throughput as well. In fact, all of the major heavy trucking manfacturers are investing heavily into developing this technology; Freightliner debuted an autonomous truck last year that is licenced to operate in Nevada, although it does still require a licensed human driver. The holdups would be opposition by the Teamsters and similar organizations, though they’ve already been weakened by deregulation and companies like Wal-Mart taking logistics in house. There is also the issue of getting these trucks approved to operate in all 48 states in CONUS (or in all the members states of the EU, or wherever) such that they can transport across long distances without having to switch from an autopilot to a human operator, but I expect once a few states get on board and realize reductions in accidents, others will rapidly follow suite.
It will, however, make for a very awkward reboot of classic truckin’ movies when 'Seventies nostaglia becomes popular again. It’ll be more like Colossus: The Forbin Project meets Smokey and the Bandit, and I don’t care how good of a Burt Reynolds impression Bradley Cooper can do, he and Jennifer Lawrence are going to end up getting caught by Robosheriff Justice five miles east of the Mississippi as he disabled their blocker car and had a satellite tracker on their truck since they left Texarkana. And, David O. Russell, you sir are no Hal Needham! Don’t even think of remaking Stroker Ace!
Stranger
I find it odd that this thread has gone for two pages with a very large unstated assumption.
Whyever would a car look for a stoplight? Those are for the limited, meatbag, drivers. One of the core ideas is that the car will actively communicate - with stoplights, other cars, temporary signs, etc etc.
Car approaches intersection. A transmitter at the light control box tells the car the current light state, and when the green will change to red. Car calculates & decides whether it can make it through the intersection or not. Car communicates with other cars to decide which has priority if there is a potential for collision. Stop sign has a transmitter saying its there, probably gives GPS coordinates so the car knows exactly where to stop. School zone light is on? Car gets told that so it can slow. Temporary light? Has its own transmitter. Once you reach critical mass or legislate away drivered cars, you can even get rid of the light and sign portions.
Spoofing and jamming (security in general) are problems to be solved, but that would be a human problem anyway. Ditto red Barchettas ;). Maybe limited access autobahn that you can only enter while the computer is driving? Weather shouldn’t be a problem - between radar, laser, radio, high freq audio, I expect at least one of them will work in snow.
You seem to assume every car on the will be instantly replaced with a self-driving car and the infrastructure will be instantly upgraded to best accommodate them. I live in today’s United States where the average age of a car is over 11 years old, the auto industry has the capacity to replace perhaps 10% of the auto fleet per year (and that’s a generous estimate), and where Congress can take years to adopt new transportation bills that fund only a small portion of critical infrastructure needs like replacing failing bridges. The revenue from our fuel tax, which is dedicated to highway funding, is dropping in real terms because the gas tax hasn’t been raised within the lifetime of millions of drivers and the amount of fuel purchased has plateaued or perhaps begun dropping as cars become more fuel efficient, public transit and even bike commuting are increasing, people move back to cities with shorter commutes, and younger people learn to drive at lower rates than they did historically. I don’t see roads improving the way you predict. Self-driving cars are going to coexist with people-driven cars on roads just like today’s for a very long time. Everyone else is reasonably assuming that in their predictions.
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most automakers do, to some extent.
Because the world is filled with stoplights that don’t communicate with anything else except by means of the light. (Alright, they “communicate” with their controls, over wires that run from the lights to the big box with the controls in it. But those controls don’t connect to anything but power.)
If self-driving cars would have to wait until all stoplights are replaced with ones that transmit what color they are in what direction, that will be a LONG wait.
That was the plan when GM proposed self-driving cars in the 1930’s. Folks got sick of waiting, so they started working on cars that can take the infrastructure as-is.
I’ll try to be clearer.
I strongly suspect that the speed limits shown by these nav systems are not updated in anything like “real-time”. I suspect they show the speed limit at the time the map data was made, and will change if the company becomes aware that the speed limit has changed.
I strongly doubt that these nav systems are programmed to recognize the specific windows for reduced speed in a given school zone. That is, that the nav system would show the speed limit as 25 during the half hour in the morning and another half hour in the afternoon, only on weekdays and not on holidays, that the speed limit goes down to 25. I’ll bet they just say 35 all the time.
BUT, Google’s cars have better maps than your sat nav. Their map shows every stoplight and such, so I’m sure they could be given data for places like school zones where the speed limits change at predictable times.
But I also pointed out that there are some school zones where the change is less predictable. Zones where the speed limit is 25 between the time the principal turns on the lights that mark the school zone and when he turns them off. Those are going to be impossible to tell the cars about beforehand, since nobody knows about them beforehand. "From 7:30ish to sometime around 8 " is not the kind of data computers are good at working with.
But if someone is already teaching them to recognize stoplights, it won’t be very hard to teach them how to recognize flashing yellow lights on signs. And that ability would let them react to a wide variety of “when flashing” regulations.
(Around here. the most common after school zones would be “When flashing, all trucks and commercial vehicles pull in for inspection”)
this is correct.
for the most part you’re also correct, though Ford of Europe has introduced the ability for the car to read speed limit signs. Ford cars slow when they see speed-limit signs - BBC News But that wouldn’t account for signs which say “School speed limit 25 between these times.” a lot of places near me have gone to electronic speed limit signs which automatically change the displayed number on schedule.
I think this is where we’re talking past each other. you’re talking about how car sat nav works today. I’m talking about how it could work once cars are allowed to drive themselves. I already have a rectangle in my pocket which can receive real-time road information. what I’m saying is that I believe once self driving cars become available they will be connected and able to receive similar data. and since the map data is “out there” and not contained in the car, real-time updates like speed limit changes can be pulled automatically.
All self driving car prototypes are aware of pedestrians and parked cars.
Car enters what it knows to be a school zone.
Time 6am-6pm
=>1 pedestrian detected assume school zone speed
6pm-6am
=>3 pedestrian detected assume school zone speed
Doing something like that it doesent need to be spoon fed data ahead of time, you just assume detected pedestrians in school zones during “school hours” are kids and set speed accordingly. After hours might not be but its a safe bet that clusters of pedestrians around a school could be after hours activities or events that could very well be students and due caution becomes prudent. It would also cover things like mid day shuffling via bus to programs on other campuses. The car doesent need a schedule, it makes a decision based on its environment.
Thats going to be a ton of upgrades to traffic infrastructure upgrades.
An easier solution would be to ask the driver to “touch the traffic signal” on a picture from the cars forward cameras on one of the dashboard displays.
By combining the known gps coordinates and direction of travel, it will never have to ask twice about a given light.
Multiplied by hundreds of cars making dozens of trips a week, massively crowdsourced traffic signal location data could have good info on a major city in a few weeks. Send a few cars with company reps to cruise most of the main surface streets for a couple weeks doing the same to “prelocate” traffic control devices, and the car owners pick up the oddballs and strays.
Google Maps and Waze are two map applications that already give real time traffic data - there’s no reason to think that things like school zone timings similarly couldn’t be updated to adapt to such variables.
Sure its complex - but not amazingly difficult.