# Flashing your high-beams **URL:** \ **Category:** In My Humble Opinion\ **Created:** [November 19, 2014, 2:21am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034 "2014-11-19T02:21:13Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Mr.Kobayashi](https://avatars.discourse-cdn.com/v4/letter/m/4af34b/32.png) [@Mr.Kobayashi](https://boards.straightdope.com/u/Mr.Kobayashi)\ **Post date:** [November 19, 2014, 2:21am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/1 "2014-11-19T02:21:13Z")
…you get shot by gangsters! No, not that one. You’re driving along the public highway in the middle of the night. In a lay-by, you see some 5-0 with a mobile speed camera (they look like [this in the UK](http://i.dailymail.co.uk/i/pix/2010/05/21/article-0-09B05D60000005DC-447_468x361.jpg)), I think you call them [police traps](http://pricinginsider.carsdirect.com/wp-content/uploads/2012/05/florida-flashing-headlights-speed-trap-free-speech1.jpg) in the USA. You round the corner out of sight of the police and see another motorist going in the opposite direction. They’re going slightly over the speed limit, not ridiculously so - say about 35mph in a 30mph zone. Do you flash your beams to warn 'em of the speed trap? ---
**Author:** ![The\_Joker\_and\_the\_Thief](https://avatars.discourse-cdn.com/v4/letter/t/e79b87/32.png) [@The\_Joker\_and\_the\_Thief](https://boards.straightdope.com/u/The_Joker_and_the_Thief)\ **Post date:** [November 19, 2014, 2:28am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/2 "2014-11-19T02:28:45Z")
I’d think to flash my high beams right as I passed them, then I’d kick myself for not doing so, followed by second guessing myself for the next twenty minutes. Also, I’d be staring at the rear-view to see if they got pulled over. ---
**Author:** ![kopek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kopek/32/337_2.png) [@kopek](https://boards.straightdope.com/u/kopek)\ **Post date:** [November 19, 2014, 3:06am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/3 "2014-11-19T03:06:01Z")
I’m kinda with **JOKER** although I will admit to, once or twice in my life, using a speeder going my direction as a rabbit – fall in a middling ways back at about his speed and letting him trip the bear. ---
**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:** [November 19, 2014, 3:15am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/4 "2014-11-19T03:15:04Z")
I used to flash all the time. Now as I am getting older (more curmudgeonly), fuck it. You’re speeding then you deserve to get caught. The reason for speed traps is presumably for public safety. You made your bed; you lie in it. Not my problem. ---
**Author:** ![sparky\_1](https://avatars.discourse-cdn.com/v4/letter/s/77aa72/32.png) [@sparky\_1](https://boards.straightdope.com/u/sparky_1)\ **Post date:** [November 19, 2014, 3:19am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/5 "2014-11-19T03:19:16Z")
I always flash my lights off/on to warn them. Speeders aren’t the issue, it’s the inattentive drivers who are. I figure if my flashing my lights doesn’t catch their attention, then they _really_ deserve a ticket. ---
**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\ **Post date:** [November 19, 2014, 4:25am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/6 "2014-11-19T04:25:03Z")
> [@The\_Joker\_and\_the\_Thief](#): > > I’d think to flash my high beams right as I passed them, then I’d kick myself for not doing so, followed by second guessing myself for the next twenty minutes. Also, I’d be staring at the rear-view to see if they got pulled over. I don’t really think I ought to flash, but, if I did, I also would almost certainly fail to think of doing so in time. Furthermore, if was the person getting flashed, I would have gone gone through the speed trap long before I figured out what, if anything, the flash was trying to tell me. Indeed, I think the chances of me _ever_ figuring out what, if anything, the flash was trying to tell me are quite remote (unless, perhaps, I heard the sirens and got pulled over almost immediately after seeing it). It is certainly news to me that a headlight flash (even when I can tell it from the approaching vehicle going over a bump, or something) can reliably, or even often, be interpreted to mean “Look out, there is a speed trap ahead of you”. In short, flashing is not only wrong, it is also, almost certainly, pointless. ---
**Author:** ![DinoR](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dinor/32/2821_2.png) [@DinoR](https://boards.straightdope.com/u/DinoR)\ **Post date:** [November 19, 2014, 4:35am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/7 "2014-11-19T04:35:12Z")
> [@Mr.Kobayashi](#): > > You round the corner out of sight of the police and see another motorist going in the opposite direction. They’re going slightly over the speed limit, not ridiculously so - say about 35mph in a 30mph zone. Do you flash your beams to warn 'em of the speed trap? I can’t reasonably tell at an extended distance how fast people closing on me are going unless they are significantly above or below normal. It’s not till they get closer/pass that I get a better idea. Even then 5mph in a 65mph closing speed is pretty small difference to gauge with any kind of accuracy. If I can tell at a distance that they are speeding we’re more in to the “ridiculously so” category. In which case, let them get the ticket for everyone’s safety. I’ll flash if it’s one of the sudden drops that seem counter-intuitve speed traps. That has nothing to do with how fast or slow the oncoming driver is going. It’s all about a warning to watch out for the sudden change (and the nice officer sitting with his radar aimed 10 feet past the speed limit changing sign.) ---
**Author:** ![Suburban\_Plankton](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/suburban_plankton/32/219_2.png) [@Suburban\_Plankton](https://boards.straightdope.com/u/Suburban_Plankton)\ **Post date:** [November 19, 2014, 5:39am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/8 "2014-11-19T05:39:26Z")
It would never occur to me to flash my high-beams to warn someone of a speed trap. And if someone flashed me, I’d have no idea why. ---
**Author:** ![doorhinge](https://avatars.discourse-cdn.com/v4/letter/d/a5b964/32.png) [@doorhinge](https://boards.straightdope.com/u/doorhinge)\ **Post date:** [November 19, 2014, 6:06am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/9 "2014-11-19T06:06:31Z")
I’ll flash my high beams 3 times in rapid succession. I do not feel responsible for the other drivers lack of understanding. On the other hand, professional truck drivers do understand what flashing your lights means (it’s a general warning of impending danger ahead) and they will usually flash their lights once to acknowledge the warning. Based on my personal experiences. The danger could be deer playing or feeding next to the road, a disabled vehicle in the roadway, a damaged road surface, black ice, standing water, a traffic citation, whatever. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 19, 2014, 8:38am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/10 "2014-11-19T08:38:06Z")
US = speed trap. Police trap sounds like Police Cops. They’re police. They’re cops. Police Cops. With Detective Homer Simpson. Like above, I’d flash if I ever remembered to but normally I don’t. So better in theory than in practice. I don’t think I’m completely cynical to say that public safety is very very low on the reasons for speed traps. Non-quotas. ---
**Author:** ![Renee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/renee/32/287_2.png) [@Renee](https://boards.straightdope.com/u/Renee)\ **Post date:** [November 19, 2014, 11:55am UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/11 "2014-11-19T11:55:04Z")
People around here (rural Missouri) are really good about doing this, weather for deer in the road or speed traps. Friendly area. I do my part as well. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [November 19, 2014, 1:02pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/12 "2014-11-19T13:02:07Z")
Flashing your lights briefly as a warning is a courtesy to other drivers in situations where there is no real problem with speeders, but police routinely conceal themselves to harvest traffic fines as a revenue-generating mechanism. ---
**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:** [November 19, 2014, 1:10pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/13 "2014-11-19T13:10:39Z")
Do unto others. I always warn others. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [November 19, 2014, 1:37pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/14 "2014-11-19T13:37:54Z")
> [@Suburban\_Plankton](#): > > It would never occur to me to flash my high-beams to warn someone of a speed trap. And if someone flashed me, I’d have no idea why. It’s a very well established signal in the North East USA. I’d be surprised if any of my friends didn’t know this one. I do warn people, and I’ve seen them obviously slow down in response. As someone else said, they don’t know whether it’s an accident ahead or a speed trap, but they know to hit the brakes. The only exception is certain areas of the Penna Turnpike, where folks just truly need to slow down for safety’s sake. If they are obviously flying around corners in that area, I’ll do nothing and let them get caught. Better by the cops than by the cliffs. ---
**Author:** ![Lukeinva](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lukeinva/32/17872_2.png) [@Lukeinva](https://boards.straightdope.com/u/Lukeinva)\ **Post date:** [November 19, 2014, 1:43pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/15 "2014-11-19T13:43:12Z")
HBO. Help a brother out, flash and warn. ---
**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:** [November 19, 2014, 1:53pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/16 "2014-11-19T13:53:59Z")
I got flashed on the way into work this morning, but I wasn’t going fast enough over the speed limit to get ticketed. ETA: The speed limit is 90 KPH (55 MPH) and I was going 110 KPH (68 MPH). ---
**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:** [November 19, 2014, 2:06pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/17 "2014-11-19T14:06:24Z")
> [@Suburban\_Plankton](#): > > It would never occur to me to flash my high-beams to warn someone of a speed trap. And if someone flashed me, I’d have no idea why. Yeah, I’d assume they’re trying to tell me my lights are off or my own high beams were on, so I’d check them (and probably turn them off and back on again) just as I hit the speed trap, which would practically guarantee I’d get pulled over. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [November 19, 2014, 2:18pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/18 "2014-11-19T14:18:47Z")
For one thing, it would depend on how realistic I judged the speed limit to be. If there was a ridiculously low speed limit obviously intended to be a speed trap (hence the presence of the skulking cop), I’d warn the other driver. But in most US states, the general speed limit on open highways is pretty liberal, and if the other driver is going over 70, I am happy to let him subsidize my tax burden. ---
**Author:** ![BobLibDem](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/boblibdem/32/3149_2.png) [@BobLibDem](https://boards.straightdope.com/u/BobLibDem)\ **Post date:** [November 19, 2014, 2:20pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/19 "2014-11-19T14:20:36Z")
My mind is dirty enough to think of something else altogether when I saw the thread title. I’ve never considered warning other drivers. The only time I flash high beams at someone is when they appear to have forgotten to turn theirs off, or if they should have their head lights on and they don’t (like dusk). For speed traps, naw. If you’re speeding, damned if I care if you get stopped. ---
**Author:** ![Anaamika](https://avatars.discourse-cdn.com/v4/letter/a/5f9b8f/32.png) [@Anaamika](https://boards.straightdope.com/u/Anaamika)\ **Post date:** [November 19, 2014, 2:22pm UTC](https://boards.straightdope.com/t/flashing-your-high-beams/705034/20 "2014-11-19T14:22:53Z")
I know what the signal is and I’ve used it, but nowadays I just don’t bother. On the highways I set my cruise control whenever possible so I hardly go too much over the limit (I usually set it to 70 on a 65mph road). If you want to speed much faster than that, it’s your lookout. You’re not going to get there that much faster anyway (unless you are going 90, which has its own dangers), so I don’t really get why you bother. The only reason I go faster is if I get in a pack of faster cars and I can keep pace for a while. Or passing. [Next page](https://boards.straightdope.com/t/flashing-your-high-beams/705034.md?page=2)