# Why do we have stop signs? **URL:** \ **Category:** Factual Questions\ **Created:** [July 27, 2010, 6:34pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211 "2010-07-27T18:34:44Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [July 28, 2010, 5:52am UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/61 "2010-07-28T05:52:18Z")
> [@Ferret\_Herder](#): > > > [@pulykamell](#): > > > > Apparently, some of these roundabouts, as I discovered have traffic signals stopping oncoming traffic (which is what I expected), while others do not and you’re supposed to yield to traffic that’s already on the circle. Which is counterintuitive to me. When I see “green,” I assume it means go, and you have the right of way. > > I would treat them like the onramps in the Twin Cities that had red/green lights on them. When the light turns green, you’re allowed to merge onto the highway, but you still have to yield to cars that are already there. Oh, we got those here in Chicago, too (although they are loosely obeyed.) The traffic-signal-controlled roundabout with signals only on the through streets and not on the roundabout itself, like the on-ramp lights, I just don’t get the point of. If I have to yield to the traffic on the roundabout anyway, what is the purpose of the traffic signal? Obviously, it must be advantageous to stop the feed onto the roundabout for some reason, but I don’t quite see why. If the roundabout is so full of traffic, the feeds can’t merge into it anyway. If the roundabout is empty, what’s the point of stopping the traffic? I’m sure there must be a logical explanation for it, but I haven’t figured it out. ---
**Author:** ![Cugel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cugel/32/1199_2.png) [@Cugel](https://boards.straightdope.com/u/Cugel)\ **Post date:** [July 28, 2010, 6:09am UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/62 "2010-07-28T06:09:32Z")
> [@pulykamell](#): > > Obviously, it must be advantageous to stop the feed onto the roundabout for some reason, but I don’t quite see why. When traffic is heavy in one direction, it’s difficult to enter the roundabout from the “next one round”. The lights let those drivers get a look in. In normal traffic conditions, they’re unneeded, and may not be operational. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [July 28, 2010, 6:26am UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/63 "2010-07-28T06:26:13Z")
> [@Cugel](#): > > > [@pulykamell](#): > > > > Obviously, it must be advantageous to stop the feed onto the roundabout for some reason, but I don’t quite see why. > > When traffic is heavy in one direction, it’s difficult to enter the roundabout from the “next one round”. The lights let those drivers get a look in. In normal traffic conditions, they’re unneeded, and may not be operational. Of course. That makes sense. ---
**Author:** ![jackdavinci](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackdavinci/32/3259_2.png) [@jackdavinci](https://boards.straightdope.com/u/jackdavinci)\ **Post date:** [July 28, 2010, 6:33am UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/64 "2010-07-28T06:33:47Z")
Yeah, assuming people actually yield, I wouldn’t mind this at all. I don’t really see a need for a full three second stop, when simply slowing down to 5mph and stopping completely if there is anyone else there is sufficient. Sounds like some people have seen this done is their areas. Where I am, Long Island, it would of course need a slight change in the definition of yield, if not in actual law, than at least in perception. I guess it’s different in other places, but here, I have never ever seen a yield sign at an actual 90° intersection. I’ve only seen it at road merges, or at T-intersections with a small turning lane that resembles a merge. > [@Ferret\_Herder](#): > > When you went in for a road test, the tester directed you along a route that included at least one uncontrolled intersection. How do you know? The only experience I have with uncontrolled intersections is parking lots. Which is fine, because you know to expect that from it being a parking lot. What clues are there if it’s a regular street? > [@'\[Undecided](#): > > Adrian;12733934’]It’s always assumed that you have right of way if there’s no sign? That’s strange… The alternative being, that you have to stop at every. single. intersection. It’s easier and cheaper to have “not right of way” (stop or yield) signs than “right of way” signs. And having signs is generally more beneficial to traffic flow than constant braking. I don’t see the need for a stop sign at T-sections, because it’s obvious that you have to stop and/or yield if you are on the side street. But it’s still nice to have, just for clarity and consistency. ---
**Author:** ![\_Undecided\_Adrian](https://avatars.discourse-cdn.com/v4/letter/_/eada6e/32.png) [@\_Undecided\_Adrian](https://boards.straightdope.com/u/_Undecided_Adrian)\ **Post date:** [July 28, 2010, 6:49am UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/65 "2010-07-28T06:49:00Z")
You don’t stop at every intersection here. If there’s no sign, you have to yield to the right, but that’s easy to do without completely stopping if nobody comes from there. Stop signs are very rare here (only for dangerous intersections with poor visibility, basically). ---
**Author:** ![flodnak](https://avatars.discourse-cdn.com/v4/letter/f/838e76/32.png) [@flodnak](https://boards.straightdope.com/u/flodnak)\ **Post date:** [July 28, 2010, 7:26am UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/66 "2010-07-28T07:26:19Z")
Norway is another country with very few stop signs (and when you see them, you by god STOP, because you know there’s a very good reason that involves keeping all your body parts functioning and attached to one another). If the road you are driving on is a priority road, meaning you don’t have to yield to traffic coming from the right, this is indicated by a diamond sign placed at regular intervals along the road, though rarely at the intersection itself. If you don’t see that sign, normal yield rules apply. Norwegian traffic engineers are also very fond of traffic circles/roundabouts, and everyone knows the rules for those, as well. They tend to reserve traffic lights for high-traffic intersections where traffic circles wouldn’t work well. On the other hand, a major intersection near my house was converted a few years ago from a light-controlled intersection to a circle, and traffic flows better now. I really do think it’s all down to driver training and driver expectations. ---
**Author:** ![GoodOmens](https://avatars.discourse-cdn.com/v4/letter/g/d26b3c/32.png) [@GoodOmens](https://boards.straightdope.com/u/GoodOmens)\ **Post date:** [July 28, 2010, 1:54pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/67 "2010-07-28T13:54:38Z")
> [@Procrustus](#): > > Hey, in Seattle we have a great number of “uncontrolled intersections.” No stop or yield sign for any driver. If you’re used to it, you handle them like a yield sign, but if you’re new to the city, you assume if you don’t have a sign telling you to stop or yield, then the other driver does and you therefore have the right of way. Big mistake. Oh, how I miss driving in Seattle. No, wait, what’s that other word? Dread. See, here in Connecticut we have stop signs, but people just ignore them. That way the signs take on the role of public art exhibits. It’s all about culture. ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [July 28, 2010, 2:10pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/68 "2010-07-28T14:10:49Z")
Connecticut also used to have (don’t know if they still do) these great signs that said “Road Legally Closed. State Liability Limited.” They would put those up anywhere there was road construction, so that half the roads in the state were legally closed. Presumably the idea was to try to get out of getting sued, although I don’t know if it worked. ---
**Author:** ![Darth\_Panda](https://avatars.discourse-cdn.com/v4/letter/d/ee7513/32.png) [@Darth\_Panda](https://boards.straightdope.com/u/Darth_Panda)\ **Post date:** [July 28, 2010, 2:14pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/69 "2010-07-28T14:14:01Z")
Where I’ve lived, we’ve never had uncontrolled intersections. As a tourist in other countries, I’ve never quite figured out when pedestrians are supposed to be able to cross the street at such places. My approach was usually to either a) wait until there wasn’t much traiffc; or b) pray to God and run like hell. Is this working as intended? ---
**Author:** ![Nars\_Glinley](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nars_glinley/32/8177_2.png) [@Nars\_Glinley](https://boards.straightdope.com/u/Nars_Glinley)\ **Post date:** [July 28, 2010, 2:51pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/70 "2010-07-28T14:51:04Z")
> [@spark240](#): > > Meanwhile, I live in a rural area, with one very small town and a grand total of one traffic _light_ in the entire county of ~380 square miles. A significant fraction of the county’s lesser roads are unpaved dirt tracks, and many of these don’t have two “lanes” of width–when cars approach from opposite directions, somebody has to run off the road a little. Until a few years back, there was actually a public road that ran _in_ a stream bed for part of its course. And yet, for all that, there are Stop signs all over the place. This is my situation as well. I live way out in the country where the roads are straight as an arrow. When I come to an intersection, I can literally see a mile in every direction and yet for some reason, I have to (legally) come to a complete stop even though I am assured that I’m the only vehicle within a one mile radius. ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [July 28, 2010, 3:44pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/71 "2010-07-28T15:44:02Z")
> [@Nars\_Glinley](#): > > > [@crazyjoe](#): > > > > Also, a 4 way yield doesn’t really help. 4 way stops allow all traffic to flow through an intersection equally. > > In my hypothetical highway world, a 4 way yield would be treated exactly like a 4 way stop except that if there’s no one coming, you wouldn’t have to stop. The problem is that many drivers are sure no one is coming when someone actually is. > [@Nars\_Glinley](#): > > **GH057,** from your story, it sounds as if your problem was with an unattentive, lawbreaking driver. Inattentive, lawbreaking drivers abound. > [@Nars\_Glinley](#): > > If he had followed the law, he would have stopped. I’m not so sure that in your situation that a stop sign would have helped. People run stop signs all of the time too. Sure. Nothing’s perfect. But when they _do_ obey them, stop signs kill their momentum, and at lower speeds, the extra time before impact greatly increases their ability to react even if their judgment and decisionmaking can’t be improved. I may be cynical, but I feel like it’s a risk to trust the judgment of other drivers too much, especially when there’s an inherent conflict of interest – a driver who doesn’t have to stop if he doesn’t see anyone may subconsciously tend to interpret what he sees in a way that doesn’t require him to slow down (yield). ---
**Author:** ![FluffyBob](https://avatars.discourse-cdn.com/v4/letter/f/ecb155/32.png) [@FluffyBob](https://boards.straightdope.com/u/FluffyBob)\ **Post date:** [July 28, 2010, 3:56pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/72 "2010-07-28T15:56:08Z")
There is so much distracted driving and general ignorance / disregard for traffic conventions and rules that ‘mindless’ measures like stop signs are necessary. Yields don’t necessarily work that well, at least weekly I have to brake to avoid someone who ignores a yield sign and cuts me off. Heck, half the drivers on the road can’t even use merge lanes properly and are confused by traffic circles. I think stop signs function a little like drills do for the military; it creates a behavior that is somewhat automatic. A drilled-in procedure of coming to a full stop and looking around breaks up a less attentive state of just cruising straight down a lane. Intersections require more attention and stop signs and traffic signals force that attention. Think how often we all drift off mentally while commuting and find we are almost home and have driven most of the way in a state of limited attention - autopilot basically. I have heard that this is associated with a natural brain state (theta waves?). Driving consists of a lot of learned, nearly automatic behaviors, and traffic signals help define those behaviors for the appropriate time. I am not going to wait five minutes for the red light at an empty intersection at 3 in the morning. I will ‘roll’ a stop sign in certain situations. But only at times when I know it is safe, and I accept the penalty of a ticket if I get caught - obviously I couldn’t have been paying enough attention if I didn’t see a cop. But I accept the necessity of the convention. ---
**Author:** ![Bearflag70](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Bearflag70](https://boards.straightdope.com/u/Bearflag70)\ **Post date:** [July 28, 2010, 4:27pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/73 "2010-07-28T16:27:59Z")
> [@Sailboat](#): > > > [@Nars\_Glinley](#): > > > > > [@crazyjoe](#): > > > > > > Also, a 4 way yield doesn’t really help. 4 way stops allow all traffic to flow through an intersection equally. > > > > In my hypothetical highway world, a 4 way yield would be treated exactly like a 4 way stop except that if there’s no one coming, you wouldn’t have to stop. > > The problem is that many drivers are sure no one is coming when someone actually is. If you use that as the basis, then a stop sign isn’t safe enough either. Entering an intersection isn’t safe because there may be someone coming that you just can’t see. People can never be trusted with their own powers of observation. May as well stay at home. Many millions of miles of driving occur every day by average people and, most the time, they don’t screw up. If we can’t trust drivers to use some prudent discretion and to trust their judgment and powers of observation, then driving itself is perhaps too dangerous for the average person. ---
**Author:** ![ChrisBooth12](https://avatars.discourse-cdn.com/v4/letter/c/e95f7d/32.png) [@ChrisBooth12](https://boards.straightdope.com/u/ChrisBooth12)\ **Post date:** [July 28, 2010, 4:36pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/74 "2010-07-28T16:36:18Z")
> [@Bearflag70](#): > > [Sacramento, CA](http://maps.google.com/maps?hl=en&q=sacramento,+ca&ie=UTF8&hq=&hnear=Sacramento,+California&gl=us&ei=m1VPTPCBC4_0swOA-Nm1Bw&ved=0CCIQ8gEwAA&ll=38.605645,-121.408764&spn=0.000676,0.001373&t=k&z=20) yield signs where you normally see stops Plus all of our downtown switches to flashing yellow flashing one direction and flashing red the other after midnight I beleive ---
**Author:** ![Sailboat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sailboat/32/461_2.png) [@Sailboat](https://boards.straightdope.com/u/Sailboat)\ **Post date:** [July 28, 2010, 4:59pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/75 "2010-07-28T16:59:35Z")
> [@Bearflag70](#): > > > [@Sailboat](#): > > > > The problem is that many drivers are sure no one is coming when someone actually is. > > If you use that as the basis, then a stop sign isn’t safe enough either. Entering an intersection isn’t safe because there may be someone coming that you just can’t see. People can never be trusted with their own powers of observation. May as well stay at home. Hey, I should have addressed that in the rest of my post! Wonder what I wrote instead? ---
**Author:** ![Bearflag70](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Bearflag70](https://boards.straightdope.com/u/Bearflag70)\ **Post date:** [July 28, 2010, 5:45pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/76 "2010-07-28T17:45:00Z")
> [@Sailboat](#): > > Hey, I should have addressed that in the rest of my post! Wonder what I wrote instead? Ah yes. I think the ordinary reasonable prudent driver should not be excessively dragged down by the lowest common denominator in the name of safety. Speed, efficiency, fuel consumption, safety, and probably a few more things, are all a big balancing act. I guess we disagree on how best to strike that balance. ---
**Author:** ![asian\_riff](https://avatars.discourse-cdn.com/v4/letter/a/ecccb3/32.png) [@asian\_riff](https://boards.straightdope.com/u/asian_riff)\ **Post date:** [July 28, 2010, 7:05pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/77 "2010-07-28T19:05:38Z")
> [@Ferret\_Herder](#): > > > [@billfish678](#): > > > > Is that even legal there? I can understand the local authorities not giving a crap and not having any signs. But to legally not have something at every intersection just boggles my mind. > > I grew up in a small city in Wisconsin which had a small number of uncontrolled intersections. They’re legal, even covered in the “rules of the road” code and everything. When you went in for a road test, the tester directed you along a route that included at least one uncontrolled intersection. > > (And yes, I nearly failed because I wasn’t expecting to encounter one of those. :smack: ) Me too. Not a small town, either. The instructor took me through an uncontrolled, blind intersection, which according to the vehicle code has a speed limit of 15 mph, IIRC. Unfortunately, because of cars parked on the street blocking my line of sight, it was literally impossible to even _see_ the intersection until you were practically in it. I finally was able to see that there was a cross street, and was about to slow down, when the instructor panicked and yelled, “There’s an intersection here”, and subsequently failed me. I thought it a rather unfair test. The instructor already _knew_ the intersection was there. Also, when I was growing up, changing the signals to flash at night was the norm. ---
**Author:** ![Ignatz](https://avatars.discourse-cdn.com/v4/letter/i/3be4f8/32.png) [@Ignatz](https://boards.straightdope.com/u/Ignatz)\ **Post date:** [July 28, 2010, 10:35pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/78 "2010-07-28T22:35:45Z")
> [@Bearflag70](#): > > [Here’s](http://www.ctre.iastate.edu/pubs/itcd/yields.pdf) a traffic engineering thing on installing stop vs. yield signs. [PDF] This reference refers to a document that has had two complete revisions since 2000. The latest MUTCD (_Manual on Uniform Traffic Control Devices_) is from 2009 and has the force of federal (and most states’) law. For the pages of the 900+ page manual that deal with right-of-way, stop, and yield signs, see pages 50 thru 54 of Part 2B. Enjoy. > **[part2b.pdf](https://mutcd.fhwa.dot.gov/pdfs/2009/part2b.pdf)** > > 2.86 MB ---
**Author:** ![Bearflag70](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Bearflag70](https://boards.straightdope.com/u/Bearflag70)\ **Post date:** [July 29, 2010, 3:31pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/79 "2010-07-29T15:31:58Z")
> [@Ignatz](#): > > > [@Bearflag70](#): > > > > [Here’s](http://www.ctre.iastate.edu/pubs/itcd/yields.pdf) a traffic engineering thing on installing stop vs. yield signs. [PDF] > > This reference refers to a document that has had two complete revisions since 2000. The latest MUTCD (_Manual on Uniform Traffic Control Devices_) is from 2009 and has the force of federal (and most states’) law. For the pages of the 900+ page manual that deal with right-of-way, stop, and yield signs, see pages 50 thru 54 of Part 2B. Enjoy. > > [http://mutcd.fhwa.dot.gov/pdfs/2009/part2b.pdf](http://mutcd.fhwa.dot.gov/pdfs/2009/part2b.pdf) That link is an interesting read about how and when to use certain signs. One sentence made me laugh out loud: > [@](#): > > STOP signs and YIELD signs shall not be mounted on the same post. I can only imagine there is some idiot working for some city somewhere who necessitated putting that little tidbit in the document. ---
**Author:** ![Nars\_Glinley](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nars_glinley/32/8177_2.png) [@Nars\_Glinley](https://boards.straightdope.com/u/Nars_Glinley)\ **Post date:** [July 30, 2010, 3:44pm UTC](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211/80 "2010-07-30T15:44:28Z")
> [@Bearflag70](#): > > > [@](#): > > > > STOP signs and YIELD signs shall not be mounted on the same post. > > I can only imagine there is some idiot working for some city somewhere who necessitated putting that little tidbit in the document. Not quite the same thing but an interesting idea [here.](http://www.nashuatelegraph.com/news/793917-196/should-we-put-a-stop-to-.html) It’s a stop/yield hybrid that says “Take Turns”. I like it. [Previous page](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211.md?page=3) [Next page](https://boards.straightdope.com/t/why-do-we-have-stop-signs/548211.md?page=5)