# self driving cars and speed limits **URL:** \ **Category:** Factual Questions\ **Created:** [May 30, 2015, 5:11am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179 "2015-05-30T05:11:05Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [May 31, 2015, 2:15am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/21 "2015-05-31T02:15:15Z")
I don’t disagree, but the fact is that traffic fines are a large revenue stream, and if that revenue stream disappears or is severely reduced the money to replace it will have to come from somewhere. I foresee a surge in jaywalking citations! ---
**Author:** ![Sinaptics](https://avatars.discourse-cdn.com/v4/letter/s/278dde/32.png) [@Sinaptics](https://boards.straightdope.com/u/Sinaptics)\ **Post date:** [May 31, 2015, 2:44pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/22 "2015-05-31T14:44:31Z")
> [@Spoke](#): > > When the idea of writing speeding tickets is obsolete, how will law enforcement agencies and local governments replace that very large revenue stream? Won’t traffic cops be altogether obsolete once self-driving cars are ubiquitous? Personally, I wonder how municipalities are going to handle the reduction in revenue. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [June 1, 2015, 2:39am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/23 "2015-06-01T02:39:00Z")
> [@Smapti](#): > > There are very few scenarios where it is acceptable for a _human_ driver to go beyond 2-3 mph in excess of the speed limit. Well, two obvious ones: [ul] [li]Not impeding traffic.[/li][li]Forcing the speed limit to change to one that’s reasonable. A lot of traffic management policies follow the 85% or 90% percentile rule.[/li][/ul] ---
**Author:** ![cmosdes](https://avatars.discourse-cdn.com/v4/letter/c/a587f6/32.png) [@cmosdes](https://boards.straightdope.com/u/cmosdes)\ **Post date:** [June 1, 2015, 3:02am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/24 "2015-06-01T03:02:37Z")
> [@Smapti](#): > > There are very few scenarios where it is acceptable for a _human_ driver to go beyond 2-3 mph in excess of the speed limit. > > I would expect far better from a computer. I have no idea where you drive, but around here anyone driving on a highway 2-3mph over the speed limit will be passed by 95% of the other drivers around. Even in town, most drivers are doing at least a few mph over the speed limit, but not usually more than 7 or 8 mph. The only places I see drivers strictly adhere to the posted speed limits are through school zones. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [June 1, 2015, 3:27am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/25 "2015-06-01T03:27:06Z")
> [@Sinaptics](#): > > Won’t traffic cops be altogether obsolete once self-driving cars are ubiquitous? Personally, I wonder how municipalities are going to handle the reduction in revenue. A lot of cops spend their time dealing with breakdowns, which are still going to happen. Given court costs etc., I’d be surprised if most places make a lot of money on tickets. If California did you’d think more cops would be out there. ---
**Author:** ![stui\_magpie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/stui_magpie/32/11010_2.png) [@stui\_magpie](https://boards.straightdope.com/u/stui_magpie)\ **Post date:** [June 1, 2015, 4:25am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/26 "2015-06-01T04:25:01Z")
> [@cmosdes](#): > > I have no idea where you drive, but around here anyone driving on a highway 2-3mph over the speed limit will be passed by 95% of the other drivers around. > > Even in town, most drivers are doing at least a few mph over the speed limit, but not usually more than 7 or 8 mph. > > The only places I see drivers strictly adhere to the posted speed limits are through school zones. Interesting. In Victoria we get bombarded with messages about how speeding kills and even had a advertising campaign “Wipe off 5” suggesting people drive 5kmh slower than the speed limit. I routinely on freeways set the cruise control for 2kmh over the speed limit and pass almost everything on the road. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [June 1, 2015, 9:52am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/27 "2015-06-01T09:52:39Z")
> [@Voyager](#): > > A lot of cops spend their time dealing with breakdowns, which are still going to happen. Given court costs etc., I’d be surprised if most places make a lot of money on tickets. If California did you’d think more cops would be out there. Most people simply mail in the fine and don’t use court time. The last time I had a ticket (this was sometime before 9/11) I did take it to court, and everyone there had to pay court costs in addition to their fine. I had my ticket dismissed, but still had to pay court costs that (probably not coincidentally) were equal to the would-be fine. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [June 1, 2015, 1:45pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/28 "2015-06-01T13:45:47Z")
> [@panache45](#): > > Is the cop human or self-ticketing? Good point–the car could just contact the police and ask them to submit a ticket by email whenever it breaks the speed limit. That’d be a great time-saver, and paper-free as well. :dubious: ---
**Author:** ![doorhinge](https://avatars.discourse-cdn.com/v4/letter/d/a5b964/32.png) [@doorhinge](https://boards.straightdope.com/u/doorhinge)\ **Post date:** [June 1, 2015, 2:42pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/29 "2015-06-01T14:42:43Z")
When legislatures finally get around to creating laws allowing the public’s use of driverless cars, on public roads, I assume that driverless cars will not be allowed, by law, to exceed the legal speed limit. If the software/hardware malfunctioned, and driverless vehicles were to routinely, or even occasionally, exceed the posted limit, the manufacturer could be held responsible for creating an unsafe vehicle. Unless the same legislators pass a law exempting the manufacturer from liability. ---
**Author:** ![Spoke](https://avatars.discourse-cdn.com/v4/letter/s/a88e57/32.png) [@Spoke](https://boards.straightdope.com/u/Spoke)\ **Post date:** [June 1, 2015, 8:19pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/30 "2015-06-01T20:19:25Z")
> [@Voyager](#): > > A lot of cops spend their time dealing with breakdowns, which are still going to happen. Given court costs etc., I’d be surprised if most places make a lot of money on tickets. If California did you’d think more cops would be out there. [Oh, it’s a lucrative enterprise](http://www.statisticbrain.com/driving-citation-statistics/). > [@](#): > > Average annual speeding ticket revenue per U.S. police officer $300,000 And that is evidently per all police officers across the board, not just traffic cops. So the revenue traffic cops generate must be extremely large to bring the per-police-officer average that high. ---
**Author:** ![Doug\_K](https://avatars.discourse-cdn.com/v4/letter/d/b5ac83/32.png) [@Doug\_K](https://boards.straightdope.com/u/Doug_K)\ **Post date:** [June 1, 2015, 9:02pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/31 "2015-06-01T21:02:34Z")
> [@Hail\_Ants](#): > > Why do you think they will exceed the speed limit? GPS devices have been able to know the speed limit of every road your on for years now and alert you with an alarm if you exceed it (if desired). Linking this into a self-driving system is a no-brainer. I routinely drive on many roads where my GPS doesn’t know the speed limit, and also many roads where it thinks it does, but is wrong, in some cases by as much as 10 mph off. ---
**Author:** ![ssgenius](https://avatars.discourse-cdn.com/v4/letter/s/b5ac83/32.png) [@ssgenius](https://boards.straightdope.com/u/ssgenius)\ **Post date:** [June 1, 2015, 11:25pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/32 "2015-06-01T23:25:37Z")
Yes, I like the idea of driverless cars and using computers to automate driving if possible. However, I see big problems with the implementation and I don’t think they have been fully thought through just yet. Okay, so one and his/her family gets on a driverless car and tells it to go to San Diego and then goes to sleep while driving overnight. How well do you think the group is going to sleep while this driverless car is going down the road with all the bumps and bounces and road turns. What about bad weather? How would it deal with that? Try driving through an ice storm with one. Lots of work to deal with that. How about through a blizzard and a snow storm How about a deluge of rain where there is high water. Is it set up to deal with that? How would it detect the high water? Cars right now are not set up for sleeping accommodations right now and to add that in would make the car a lot more expensive and more thirsty for fuel. This would have the effect of increasing the fuel consumption nationally (I am just taking about the USA) as it would be much more common to travel with these driverless cars at night and the number of trips would increase dramatically Not only that it would have repercussion’s on the entire hotel industry as instead of staying in a hotel, why not use these driverless cars for the overnight stays. What about the wear and tear on the roads with the increased traffic? Who pays for that? Could these driverless cars be retrofitted to older existing models. There are lot of vehicles that have been paid for and are still in great shape. Adding this option to an existing car would be a great idea, if do-able but it may be easier to just rebuild it completely This whole thing reminds me a an old cartoons magazine issue (The magazine was called Cartoons) and in one story, the entire state of California was paved over (this was in the 70s no less) and instead of having freeways, you just pointed the car in any direction and went that way. I will see if I can find if that issue is online somewhere. It was hilarious in a way ---
**Author:** ![ssgenius](https://avatars.discourse-cdn.com/v4/letter/s/b5ac83/32.png) [@ssgenius](https://boards.straightdope.com/u/ssgenius)\ **Post date:** [June 1, 2015, 11:41pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/33 "2015-06-01T23:41:05Z")
Sorry, can’t find that issue but the story was that with California completely paved over, people just lived in their cars and keep moving all day and night all over that state If I remember right the kids went to school by transferring from their car to a school bus where they learned their lessons while travelling on the school bus only to return to their car at night. Don’t remember much more about the issue aside from that. What that has to do with self driving cars, I don’t know but it made me think of that old comic ---
**Author:** ![ssgenius](https://avatars.discourse-cdn.com/v4/letter/s/b5ac83/32.png) [@ssgenius](https://boards.straightdope.com/u/ssgenius)\ **Post date:** [June 2, 2015, 5:35am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/34 "2015-06-02T05:35:23Z")
> [@ssgenius](#): > > Yes, I like the idea of driverless cars and using computers to automate driving if possible. > > However, I see big problems with the implementation and I don’t think they have been fully thought through just yet. > > Okay, so one and his/her family gets on a driverless car and tells it to go to San Diego and then goes to sleep while driving overnight. > > How well do you think the group is going to sleep while this driverless car is going down the road with all the bumps and bounces and road turns. > > What about bad weather? How would it deal with that? Try driving through an ice storm with one. Lots of work to deal with that. How about through a blizzard and a snow storm > > How about a deluge of rain where there is high water. Is it set up to deal with that? How would it detect the high water? > > Cars right now are not set up for sleeping accommodations right now and to add that in would make the car a lot more expensive and more thirsty for fuel. > > This would have the effect of increasing the fuel consumption nationally (I am just taking about the USA) as it would be much more common to travel with these driverless cars at night and the number of trips would increase dramatically > > Not only that it would have repercussion’s on the entire hotel industry as instead of staying in a hotel, why not use these driverless cars for the overnight stays. > > What about the wear and tear on the roads with the increased traffic? Who pays for that? > > Could these driverless cars be retrofitted to older existing models. > > There are lot of vehicles that have been paid for and are still in great shape. Adding this option to an existing car would be a great idea, if do-able but it may be easier to just rebuild it completely > > This whole thing reminds me a an old cartoons magazine issue (The magazine was called Cartoons) and in one story, the entire state of California was paved over (this was in the 70s no less) and instead of having freeways, you just pointed the car in any direction and went that way. I will see if I can find if that issue is online somewhere. > > It was hilarious in a way I put this in the wrong thread on driverless cars but I don’t know how to move it to the other driverless car thread:smack: ---
**Author:** ![fubar.gr](https://avatars.discourse-cdn.com/v4/letter/f/898d66/32.png) [@fubar.gr](https://boards.straightdope.com/u/fubar.gr)\ **Post date:** [June 2, 2015, 9:22am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/35 "2015-06-02T09:22:44Z")
> [@Doug\_K](#): > > I routinely drive on many roads where my GPS doesn’t know the speed limit, and also many roads where it thinks it does, but is wrong, in some cases by as much as 10 mph off. There are several cars already that can read the speed limit from roadsigns and automatically adapt the cruise control speed or alert the driver for overspeeding > **[Traffic-sign recognition](https://en.wikipedia.org/wiki/Traffic_sign_recognition)** > > Traffic-sign recognition (TSR) is a technology by which a vehicle is able to recognize the traffic signs put on the road e.g. "speed limit" or "children" or "turn ahead". This is part of the features collectively called ADAS. The technology is being developed by a variety of automotive suppliers to improve the safety of vehicles. It uses image processing techniques to detect the traffic signs. The detection methods can be generally divided into color based, shape based and learning based method... Something as advanced as the googlecar wouldn’t have the slightest problem with that. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [June 2, 2015, 10:26am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/36 "2015-06-02T10:26:06Z")
> [@ssgenius](#): > > I put this in the wrong thread on driverless cars but I don’t know how to move it to the other driverless car thread:smack: One day soon your car will be able to do things like that for you. ---
**Author:** ![Leaffan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leaffan/32/299_2.png) [@Leaffan](https://boards.straightdope.com/u/Leaffan)\ **Post date:** [June 2, 2015, 10:50am UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/37 "2015-06-02T10:50:21Z")
> [@stui\_magpie](#): > > Interesting. In Victoria we get bombarded with messages about how speeding kills and even had a advertising campaign “Wipe off 5” suggesting people drive 5kmh slower than the speed limit. > > I routinely on freeways set the cruise control for 2kmh over the speed limit and pass almost everything on the road. I don’t think you’ll find any place in Canada where people don’t routinely drive 15% - 20% above the posted speed limit and no one bats an eye. School zones may be the exception. I drive on a 90 KPH highway 5 days a week and set my cruise control at 110. The OPP (Ontario Provincial Police) don’t even give me a second glance. ---
**Author:** ![Fuzzy\_Dunlop](https://avatars.discourse-cdn.com/v4/letter/f/848f3c/32.png) [@Fuzzy\_Dunlop](https://boards.straightdope.com/u/Fuzzy_Dunlop)\ **Post date:** [June 2, 2015, 12:34pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/38 "2015-06-02T12:34:23Z")
> [@Smapti](#): > > There are very few scenarios where it is acceptable for a _human_ driver to go beyond 2-3 mph in excess of the speed limit. Actually, there are very few scenarios where it’s NOT acceptable for a human driver to go more than 2-3 mph over the speed limit. If she were driving in a parade, for instance. Although in that case it’d be more of an ad hoc parade speed than the normal speed limit for that road. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 2, 2015, 2:48pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/39 "2015-06-02T14:48:18Z")
Why does everyone keep bringing up bad weather? That is indeed a major difference between human drivers and computers, but it’s exactly the other way around: Humans cannot safely drive in bad weather, but computers, which have access to a variety of sensors humans lack, can. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [June 2, 2015, 3:02pm UTC](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179/40 "2015-06-02T15:02:30Z")
> [@ssgenius](#): > > I put this in the wrong thread on driverless cars but I don’t know how to move it to the other driverless car thread:smack: > [@kayaker](#): > > One day soon your car will be able to do things like that for you. The driverless board monk\* won’t make that mistake in the first place. \*Driverless became the preferred adjective for anything automated as driverless cars led to the necessary improvements and approvals for intelligent systems to take over most everything. Board monks were named in honor of Douglas Adams’ Electric monks from the first Dirk Gently book, which were devices that believed for you. [Previous page](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179.md?page=1) [Next page](https://boards.straightdope.com/t/self-driving-cars-and-speed-limits/721179.md?page=3)