# Have any car manufacturers included automatic turn signals on their cars? **URL:** \ **Category:** Factual Questions\ **Created:** [September 20, 2015, 10:34pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015 "2015-09-20T22:34:08Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![SpyOne](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@SpyOne](https://boards.straightdope.com/u/SpyOne)\ **Post date:** [September 23, 2015, 2:10am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/41 "2015-09-23T02:10:14Z")
> [@aceplace57](#): > > Brake lights come on when you press the brake pedal. Why don’t turn signals activate when the steering wheel is turned significantly? Because that isn’t when you are supposed to turn on your turn signal? When making a turn at an intersection, you are supposed to turn on your signal as you approach. (When and where I took my test, it was 8 seconds before turning.) Ditto for lane changes: it is supposed to signal your _intent_ to change lanes, not that you have already begun doing so. Also, the system you describe would often be activated by curves, so in addition to not coming on when it is supposed to, it will come on when it isn’t supposed to. That, in a nutshell, is why nobody has done that. ---
**Author:** ![SpyOne](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@SpyOne](https://boards.straightdope.com/u/SpyOne)\ **Post date:** [September 23, 2015, 2:17am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/42 "2015-09-23T02:17:08Z")
> [@running\_coach](#): > > Back in the 80s, I had an aftermarket brakelight on my motorcycle that did exactly that. > With increasing braking force, the light would flash faster, brighter and the flashes would be shorter in duration and closer together. > > it also adjusted for ambient light levels. Back when all third brake lights were aftermarket accessories, there was one that contained an accelerometer and got brighter under hard braking. I thought that was brilliant. Another good signal I’ve seen: many city buses include a yellow light on the back to signal neither the brake nor gas is being pressed. Some include a green light for when the gas is pressed. I often wish cars had those. ---
**Author:** ![BKCA](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@BKCA](https://boards.straightdope.com/u/BKCA)\ **Post date:** [June 23, 2019, 10:17pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/43 "2019-06-23T22:17:53Z")
Even if it’s at the last second, it does take a moment for a car to get from the middle of it’s lane to the edge where a collision could happen. If a blinking light starts in that moment I could totally see it helping to avoid a lot of accidents. Of course people should signal BEFORE they do anything, but since that’s not happening why not do this? Unless it leads to everyone just not signaling. ---
**Author:** ![OldGuy](https://avatars.discourse-cdn.com/v4/letter/o/3bc359/32.png) [@OldGuy](https://boards.straightdope.com/u/OldGuy)\ **Post date:** [June 23, 2019, 10:28pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/44 "2019-06-23T22:28:44Z")
> [@Senegoid](#): > > When the last live-human driver retires or is obsolescent, then signaling (that is, visual signaling with blinking lights anyway) will no longer be necessary.] Just too bad for the pedestrian waiting to cross at a corner with no walk light. ---
**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:** [June 23, 2019, 10:45pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/45 "2019-06-23T22:45:05Z")
> [@bob\_2](#): > > The car has satnav (gps) and knows where I am going. It should damn well anticipate the turns. It seems like this should be an easy feature to implement in cars with built-in GPS (satnav). Now that we have self-parking cars, and cars that prevent dangerous lane changes, and auto braking, the trajectory is to self-driving cars so there will be probably be no more significant enhancements to driver assist modes. ---
**Author:** ![Airman\_Doors\_USAF](https://avatars.discourse-cdn.com/v4/letter/a/e36b37/32.png) [@Airman\_Doors\_USAF](https://boards.straightdope.com/u/Airman_Doors_USAF)\ **Post date:** [June 24, 2019, 1:36am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/46 "2019-06-24T01:36:00Z")
You want mind-reading automatic turn signals? Hell, I’d be happy if BMW made them standard and not optional equipment. ---
**Author:** ![Flyer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/flyer/32/7298_2.png) [@Flyer](https://boards.straightdope.com/u/Flyer)\ **Post date:** [June 24, 2019, 2:50am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/47 "2019-06-24T02:50:35Z")
> [@LSLGuy](#): > > And in fact brake lights would be more useful if they behaved differently under gentle, typical, hard, and max effort braking. > > Then following drivers would get valuable info about what their reaction ought to be. I don’t remember off-hand where I read it, but that’s already been tried. Counter-intuitively, it actually increased accidents. People got so caught up in trying to determine how fast the car in front of them was slowing, that they forgot to actually brake themselves. > [@LSLGuy](#): > > And it was pitifully stupid advice then and is even worse today. The time you need to know somebody is thinking of turning is a few hundred feet before they do so, not a millisecond before their car changes course. You are astoundingly incorrect. Half a second of advance warning is far better than no warning at all, and very well give you just enough advantage to avoid a collision. “Watch the front wheels” is the advice I got in driver’s ed–and I went to a school that was founded by a former professional race car driver. Those guys know how to drive, whether you like their advice or not. ---
**Author:** ![running\_coach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/running_coach/32/15836_2.png) [@running\_coach](https://boards.straightdope.com/u/running_coach)\ **Post date:** [June 24, 2019, 3:13am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/48 "2019-06-24T03:13:42Z")
> [@Flyer](#): > > I don’t remember off-hand where I read it, but that’s already been tried. > > Counter-intuitively, it actually increased accidents. People got so caught up in trying to determine how fast the car in front of them was slowing, that they forgot to actually brake themselves. Back in the 80s, there was the Voedesky(I know I’m spelling it wrong) Cyberlight. It had varying flashing rates depending on braking force-faster and brighter the harder you were braking. it was not a primary brake light rather an additional light. The claim was it was tested on NYC cabs and reduced rear-enders by 60%. A local PD had them on their motorcycles which prompted me to buy one for my bike. Cars did tend to stop further back than before installation. ---
**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:** [June 24, 2019, 9:51am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/49 "2019-06-24T09:51:14Z")
> [@BrotherCadfael](#): > > The Sanity Clause says that if your driving is insane, we can lift your license. _The Catch 22 clause_ says a driver continuing to drive without asking for relief is regarded as insane, but is considered sane enough to continue driving if he does make such a request. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [June 24, 2019, 3:23pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/50 "2019-06-24T15:23:17Z")
> [@BrotherCadfael](#): > > The Sanity Clause says that if your driving is insane, we can lift your license. Come on, you ain’t foolin’ me! Everybody knows there ain’t no Sanity Clause. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [June 24, 2019, 4:03pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/51 "2019-06-24T16:03:34Z")
> [@Ravenman](#): > > I would bet even fewer people would use them then. “Ah, let the car do it. I don’t want to move my fingers.” This. It could probably be incorporated into GPS, but really, I don’t see any good coming of this. ---
**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:** [June 24, 2019, 4:16pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/52 "2019-06-24T16:16:27Z")
> [@Flyer](#): > > You are astoundingly incorrect. > > Half a second of advance warning is far better than no warning at all, and very well give you just enough advantage to avoid a collision. > > “Watch the front wheels” is the advice I got in driver’s ed–and I went to a school that was founded by a former professional race car driver. Those guys know how to drive, whether you like their advice or not. Half a second of advance warning is useless based on the [reaction time of the average driver](https://www.monash.edu/__data/assets/pdf_file/0003/217641/hfr12.pdf) (PDF file). This might not be true of a highly trained professional driver, but the vast majority of drivers get just the minimal training needed to make a car go somewhere and obey most of the laws. The bar for passing a driver’s test is pretty low. It sounds like you are making a case that turn signals are unnecessary. In Virginia, on roads where the speed limit is 35 MPH or greater you must signal for a turn 100 feet in advance. That’s a hair under 2 seconds at that speed. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [June 24, 2019, 6:31pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/53 "2019-06-24T18:31:11Z")
If you are going to change the behaviour of brake lights, it would have to be universal, and probably regulated. And you would need a public information campaign to teach people about it. Varying the brightness is a terrible idea. First, people are not good at seeing brightness changes. Second, brake lights vary in brightness already because of dirt buildup. So are those dim brake lights ahead because th pe guy is barely braking, or is he panic stopping but his car is dirty? I can imagine one system that might work… If you brake hard enough to activate ABS, have the brake lights flash in sequence. Once people get that flashing brake lights mean “I am slowing as fast as I can!”, It would be a rather intuitive interpretation. Smart cars could even detect the flash frequency and start auto-braking accordingly. The problem now is that if you don’t retrofit all cars, a car without the system might panic stop, and the person in the car behind might get fooled into thinking that it’s mild braking because no flashing is happening. Human Factors create hard problems. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [June 24, 2019, 6:41pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/54 "2019-06-24T18:41:48Z")
> [@aceplace57](#): > > . . . A late turn signal (activated automatically) would be better than none at all. As others have said, that system would be activated by curves in the road, and other things that cause any kind of swerve. Drivers will be constantly seeing automatic turn signals that do not apply to turns and will learn to ignore signals until they see some evidence that a turn is happening. That will make driving less safe. > [@Muffin](#): > > There’s something to be said for giving drivers something to do occasionally (slight bend in the road, signal a lane change, etc.) simply to help them avoid drifting off into zombie land. Sounds good to me. ---
**Author:** ![ZonexandScout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zonexandscout/32/544_2.png) [@ZonexandScout](https://boards.straightdope.com/u/ZonexandScout)\ **Post date:** [June 24, 2019, 6:44pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/55 "2019-06-24T18:44:30Z")
Use my turn signal?!? Why? Everybody who lives around her knows me and they know my car. They know I live on this street and that it’s time for me to be coming home from work. They should expect me to turn. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [June 24, 2019, 6:49pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/56 "2019-06-24T18:49:21Z")
> [@ZonexandScout](#): > > Use my turn signal?!? Why? Everybody who lives around her knows me and they know my car. They know I live on this street and that it’s time for me to be coming home from work. They should expect me to turn. That’s a joke, right? There’s a name for people who replace hard signals with expectations and guesses. They’re called crash victims. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [June 24, 2019, 11:15pm UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/57 "2019-06-24T23:15:25Z")
> [@aceplace57](#): > > 🙂 yes, that is the law. Theres a minimum number of feet to signal before the turn. It probably varies state by state. > > I see a lot of cars turning without a signal. A late turn signal (activated automatically) would be better than none at all. When I rode a motor cycle, I was grateful for small mercies: if their turn signal turned on after they changed lanes, at least I knew they _intended_ to change lanes, they weren’t just drifting across. ---
**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:** [June 25, 2019, 12:45am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/58 "2019-06-25T00:45:45Z")
> [@Sam\_Stone](#): > > If you are going to change the behaviour of brake lights, it would have to be universal, and probably regulated. In the U.S. some people do put on custom brake lights that flash. The ones I’ve seen flash when first applied to grab your attention. I’ve seen them on both cars and motorcycles, and I do not think they are stock. So it doesn’t have to be universal. > [@](#): > > If you brake hard enough to activate ABS, have the brake lights flash in sequence. Once people get that flashing brake lights mean “I am slowing as fast as I can!” I read the pitch of the car to see a car braking as hard as they can. Doesn’t leave much time to react, though, if I’m too close to start with. All of these problems with brakes and turn signals can be solved by people leaving a safe following distance, which almost nobody does because they underestimate the time needed to react to a surprise. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [June 25, 2019, 1:06am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/59 "2019-06-25T01:06:47Z")
Yeah, it could also be solved if people would learn how to use their freaking turn signals. I see people signalling AS they are turning all the time, if they bother to signal at all. The rule of thumb is that your signal light should be activated early enough that it blinks two or three times minimum before you start whatever turn you are signalling. ---
**Author:** ![california\_jobcase](https://avatars.discourse-cdn.com/v4/letter/c/9d8465/32.png) [@california\_jobcase](https://boards.straightdope.com/u/california_jobcase)\ **Post date:** [June 25, 2019, 2:13am UTC](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015/60 "2019-06-25T02:13:51Z")
Plainly audible turn signals need to return. Back in the day, you rarely saw anyone driving for miles with a signal left on because the _ **dink-dink-dink** _ of the loud thermal flasher would let you know it was on. Now too many cars’ signals are silent or nearly so, inaudible beneath road noise and the radio. [Previous page](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015.md?page=2) [Next page](https://boards.straightdope.com/t/have-any-car-manufacturers-included-automatic-turn-signals-on-their-cars/732015.md?page=4)