# Why don't red lights function as alternating stop signs? **URL:** \ **Category:** Factual Questions\ **Created:** [August 20, 2018, 2:41pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910 "2018-08-20T14:41:29Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Fotheringay-Phipps](https://avatars.discourse-cdn.com/v4/letter/f/d9b06d/32.png) [@Fotheringay-Phipps](https://boards.straightdope.com/u/Fotheringay-Phipps)\ **Post date:** [August 20, 2018, 4:37pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/21 "2018-08-20T16:37:35Z")
> [@JB99](#): > > Yes. Exactly. That is why we use stop signs, instead of lights. If I want people to proceed at their own discretion, there are other signals used for that purpose. Right. But the point is that the potential problems that you raised don’t seem to routinely happen at intersections with stop signs, which suggests that they’re not such big issues. > [@](#): > > If you turn a red light into a stop sign, then why bother having lights in the first place? Because they can alternate. The stop-signs are fixed, and the direction without the stop-sign always has the right of way, and vice versa. The idea of red lights functioning as stop-signs would be that each direction would have a turn as the one with the right of way. ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [August 20, 2018, 4:48pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/22 "2018-08-20T16:48:52Z")
> [@sbunny8](#): > > [Oregon does](https://www.oregonlaws.org/ors/811.360). Also allowed in Michigan, Washington, Alaska, Idaho. [https://axleaddict.com/safety/Obscure-Driving-Regulations-Ignorance-is-no-excuse](https://axleaddict.com/safety/Obscure-Driving-Regulations-Ignorance-is-no-excuse) ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [August 20, 2018, 4:58pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/23 "2018-08-20T16:58:20Z")
> [@Fotheringay-Phipps](#): > > Right. But the point is that the potential problems that you raised don’t seem to routinely happen at intersections with stop signs, which suggests that they’re not such big issues. You won’t accept that traffic flow and road conditions are different at different intersections, and that stop signs or lights with their different rules are chosen accordingly? ---
**Author:** ![Channing\_Idaho\_Banks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/channing_idaho_banks/32/250_2.png) [@Channing\_Idaho\_Banks](https://boards.straightdope.com/u/Channing_Idaho_Banks)\ **Post date:** [August 20, 2018, 5:03pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/24 "2018-08-20T17:03:25Z")
> [@sbunny8](#): > > [Oregon does](https://www.oregonlaws.org/ors/811.360). > > Notice it says nothing about whether the street you are on is one-way or two-way. It only says you may turn left or right if the street you’re turning onto is one-way. > > There are two major streets in Eugene that are one-way. West 7th Ave runs one-way east and West 6th Ave runs one-way west. If you’re between 6th and 7th, on one of the many north-south cross streets (almost all of which are two-way), you can make a left on red. For example, going north on Polk street (two-way), turning left onto West 6th Ave (one way), you may turn left on red. I have seen cars do this literally thousands of times, often in full view of a police car. I have never seen anyone pulled over for it, let alone ticketed. > > Yes, you are turning across a south-bound lane. But there are no cars proceeding south through that intersection because they have a red light on their side as well. They can make a right on red, turning west, at the same time that you make a left turn on red heading west. Neither of you crosses the other person’s lane. And neither of you crosses an east-bound lane. you’re taking a risk that the cars with the right-of-way that are coming from the right are not going to turn left and cross your path. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [August 20, 2018, 5:11pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/25 "2018-08-20T17:11:17Z")
> [@Fotheringay-Phipps](#): > > Right. But the point is that the potential problems that you raised don’t seem to routinely happen at intersections with stop signs, which suggests that they’re not such big issues. It’s already been pointed out that stop signs are selectively used _at intersections where these problems are less of an issue._ Fifteen years ago Panama City had virtually no traffic lights, only stop signs, even at major intersections. Traffic was an absolute nightmare. (It still is, but I shudder to think what it would be like now without stoplights.) ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [August 20, 2018, 5:23pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/26 "2018-08-20T17:23:41Z")
> [@Fotheringay-Phipps](#): > > Right. But the point is that the potential problems that you raised don’t seem to routinely happen at intersections with stop signs, which suggests that they’re not such big issues. They don’t routinely happen at intersections with stop signs, because different intersections have different traffic flow and different needs. Some streets have so much traffic that the traffic on the side street is unable to go straight or make a left turn without a light. There’s a intersection near my home where it was impossible to turn left for many years - because there was a stop sign. If I wanted to make a left turn, or go straight across the more-travelled street, I had to go around and approach the main street so that the intersection where I would cross/turn had a light rather than a stop sign. Now that they have put a light at the originally-mentioned intersection, I can actually turn left. The same thing happens on the street without stop signs- I can only really turn left off it at a light because otherwise the oncoming traffic will be too heavy. ``` Even without those issues, I've seen plenty of accidents and near accidents at all-way stops, a situation in which neither street must *always *yield the right of way and which is much closer to your idea of a red light functioning as a stop sign. ``` ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 20, 2018, 5:29pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/27 "2018-08-20T17:29:21Z")
> [@Exapno\_Mapcase](#): > > One is design. Speed bumps and humps are increasingly popular ways to force cars to slow down. . And stupid. They cause damage to your car even when you slow down. I think they should be banned. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 20, 2018, 5:31pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/28 "2018-08-20T17:31:31Z")
> [@susan](#): > > Given how many people are already whizzing through red lights (not yellow), I shudder to think of it. Not many, actually. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [August 20, 2018, 5:36pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/29 "2018-08-20T17:36:54Z")
> [@DrDeth](#): > > Not many, actually. Here in Panama, when I squeak through an intersection at the possible last second on a yellow light, there are invariably three or four cars behind me that have gone through after it turned red. 😃 ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [August 20, 2018, 5:40pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/30 "2018-08-20T17:40:02Z")
> [@Channing\_Idaho\_Banks](#): > > you’re taking a risk that the cars with the right-of-way that are coming from the right are not going to turn left and cross your path. There is a chance a car with the right of way coming from the right may continue going straight or make a left turn, so of course you don’t make the left. There is a little more to be careful of from cars from the right than when making a right on red, but not that much. I’d be more worried that a car stopped at the red opposing me decides to make a right on red as I am making the left. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [August 20, 2018, 5:56pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/31 "2018-08-20T17:56:07Z")
> [@DrDeth](#): > > And stupid. They cause damage to your car even when you slow down. I think they should be banned. There are some new bumps now with non-Newtonian fluids in them. At the correct speed they are squashed; any faster and they become rigid. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 20, 2018, 6:06pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/32 "2018-08-20T18:06:00Z")
> [@bob\_2](#): > > There are some new bumps now with non-Newtonian fluids in them. At the correct speed they are squashed; any faster and they become rigid. Interesting. ---
**Author:** ![jjakucyk](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@jjakucyk](https://boards.straightdope.com/u/jjakucyk)\ **Post date:** [August 20, 2018, 6:49pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/33 "2018-08-20T18:49:28Z")
> [@engineer\_comp\_geek](#): > > …underground wire loop…They are supposed to be set so that they’ll trigger on a motorcycle but not on a bicycle Why the hell not? Is a cyclist just supposed to wait there until a “helpful” motorist comes along to trip the sensor, or go over to press the pedestrian beg button, or just sit there until the statute of limitations runs out? > [@DrDeth](#): > > And stupid. They cause damage to your car even when you slow down. I think they should be banned. No they don’t. You’re not slowing down enough, or your car is a total piece of junk that’s not road worthy. Granted, speed humps are a bandaid solution to speeding. If speeding is a problem then the street is too wide, too clear, and too over-engineered. It’s not surprising since many states and municipalities have dropped anything with less than a 35mph design speed out of their manuals, and in some cases 40 or 45mph is their minimum design speed. That’s wholly inappropriate for any residential area, main street, and most anywhere people are present. It leads to wide lanes, sweeping curves, long sight lines, big clear zones, no parking, and large building setbacks. All those things communicate “this is a highway, go fast” so guess what happens? ---
**Author:** ![susan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/susan/32/17537_2.png) [@susan](https://boards.straightdope.com/u/susan)\ **Post date:** [August 20, 2018, 7:06pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/34 "2018-08-20T19:06:37Z")
> [@](#): > > Not many, actually. Perhaps where you live. We have a minimized police force and it’s quite common for people to run reds that were red as they approached the intersection here. My wife’s car was crushed recently by a red light runner. I see it several times a day. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [August 20, 2018, 7:10pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/35 "2018-08-20T19:10:14Z")
> [@Arcite](#): > > Every time I’m stuck at a red light and there’s no cross traffic coming at all and I’m frustrated I can’t just go, I wonder how much longer it will be until we have “smart intersections” with cameras and an AI system which can detect that there is no cross traffic coming and decide to just go ahead and change the light. there are plenty of those systems going in around me (metro Detroit.) it’s nice late at night when there’s no traffic, and as you approach a red light it turns green for you at just the right time. ---
**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\ **Post date:** [August 20, 2018, 7:11pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/36 "2018-08-20T19:11:03Z")
> [@jjakucyk](#): > > Why the hell not? Is a cyclist just supposed to wait there until a “helpful” motorist comes along to trip the sensor, or go over to press the pedestrian beg button It’s not done purposely (well, it sort of is- it’s made to not be too sensitive so false positives aren’t triggered), it’s just that a bicycle just doesn’t contain enough metal tp trigger it. Motorcycles frequently have the same issue, so several states allow motorcycles and bicycles to run the light. Bicyclists of course can also walk their bikes across the street. [https://www.bikebandit.com/blog/how-dead-red-laws-let-motorcycles-run-red-lights-legally](https://www.bikebandit.com/blog/how-dead-red-laws-let-motorcycles-run-red-lights-legally) > [@](#): > > or just sit there until the statute of limitations runs out? Won’t work. Even if you wait out the statute of limitations before proceeding (let’s say seven years), the offense was still just committed. It doesn’t matter that you reached the intersection seven years ago. It’s highly unlikely that a vehicle won’t be there to go around you and trip the sensor in all that time, though. ---
**Author:** ![DavidwithanR](https://avatars.discourse-cdn.com/v4/letter/d/3bc359/32.png) [@DavidwithanR](https://boards.straightdope.com/u/DavidwithanR)\ **Post date:** [August 20, 2018, 7:12pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/37 "2018-08-20T19:12:32Z")
> [@jjakucyk](#): > > Why the hell not? Is a cyclist just supposed to wait there until a “helpful” motorist comes along to trip the sensor, or go over to press the pedestrian beg button, or just sit there until the statute of limitations runs out? > > No they don’t. You’re not slowing down enough, or your car is a total piece of junk that’s not road worthy. > > Granted, speed humps are a bandaid solution to speeding. If speeding is a problem then the street is too wide, too clear, and too over-engineered. It’s not surprising since many states and municipalities have dropped anything with less than a 35mph design speed out of their manuals, and in some cases 40 or 45mph is their minimum design speed. That’s wholly inappropriate for any residential area, main street, and most anywhere people are present. It leads to wide lanes, sweeping curves, long sight lines, big clear zones, no parking, and large building setbacks. All those things communicate “this is a highway, go fast” so guess what happens? One residential area where I used to drive, they took to heart what you’re saying. They pulled out all the stop signs and all the yield signs. People don’t know what the hell is going on, so they slow down. It works pretty well I think. ---
**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\ **Post date:** [August 20, 2018, 7:32pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/38 "2018-08-20T19:32:39Z")
> [@jjakucyk](#): > > Why the hell not? Is a cyclist just supposed to wait there until a “helpful” motorist comes along to trip the sensor, or go over to press the pedestrian beg button, or just sit there until the statute of limitations runs out? Any sensor-controlled traffic light I have observed with any regularity has a timeout where it will cycle the lights even if no cross traffic is detected. The sensor just shortens the cycle if conditions on the main road permit. Presumably so that when a sensor fails you don’t have people waiting until the statute of limitations expires… ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [August 20, 2018, 8:11pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/39 "2018-08-20T20:11:28Z")
> [@sbunny8](#): > > FWIW, I know many many bicyclists who treat stop signs as if they are yield signs and red lights as if they are stop signs and quite a few have proposed that the law be changed to accommodate this (but only for bicycles). I don’t do this when I cycle, so it kind of pisses me off when I’m driving. If a car must stop at a red light for safety reasons, then a bike should stop for all the same reasons. I was on my bike waiting at a red light just yesterday (with a couple of other cyclists) when another cyclist just blew right past us across four lanes of traffic that had a green light. That’s just the suburbs–it’s endemic in the city. Yes, it’s more taxing on a cyclist to start and stop, but when cyclists don’t obey the rules then it erodes respect from drivers. ---
**Author:** ![glowacks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/glowacks/32/5548_2.png) [@glowacks](https://boards.straightdope.com/u/glowacks)\ **Post date:** [August 20, 2018, 8:30pm UTC](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910/40 "2018-08-20T20:30:25Z")
There are numerous left turn lights around here that will only give you a green arrow if they sense you. One of them is at an intersection where I turn left most every day when going to work. I’m in a small downtown area turning from Main onto the E-W street that becomes one of the Metro Detroit Mile Roads to the west. To the east it’s practically irrelevant, so there’s far more traffic wanting to turn west than east. If you get a case of someone who wants to turn left and fails to get sensed and then refuses to go at the end of the N-S green light cycle, the left turn lane can back up until the light does its “Ok, lets give the left turn arrow just in case our sensor is broken” phase. I try to make a left at a previous light if I can without waiting, then cut through the neighborhood, getting back to the E-W road at a light at a minor street that has far less traffic and doesn’t have a left turn light. There are plenty of others at other intersections around the metro area as well, but obviously this one I encounter a lot and so it bugs me a lot. I can see why they would want the sensor so the left turn cycle doesn’t hold up the southbound traffic when there’s no one making a left, but when it matters the most to hold up the traffic, there’s pretty much always someone turning left. Or at least, whenever I’m there, because that’s always the way I go. [Previous page](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910.md?page=1) [Next page](https://boards.straightdope.com/t/why-dont-red-lights-function-as-alternating-stop-signs/819910.md?page=3)