# "Speed limit enforced by aircraft"? **URL:** \ **Category:** Factual Questions\ **Created:** [August 12, 2002, 6:25pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575 "2002-08-12T18:25:20Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![gingersnap](https://avatars.discourse-cdn.com/v4/letter/g/f04885/32.png) [@gingersnap](https://boards.straightdope.com/u/gingersnap)\ **Post date:** [August 12, 2002, 6:25pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/1 "2002-08-12T18:25:20Z")
I see these signs in some states. How does this work, or are they just bluffing? I mean, how could an airplane read my plate number? ---
**Author:** ![Cheesesteak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cheesesteak/32/3694_2.png) [@Cheesesteak](https://boards.straightdope.com/u/Cheesesteak)\ **Post date:** [August 12, 2002, 6:32pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/2 "2002-08-12T18:32:28Z")
They don’t. They communicate with officers on the ground and direct them to the offending vehicle. They time how long it takes your car to pass a series of lines painted on the road, and calculate your speed from that. ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [August 12, 2002, 6:47pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/3 "2002-08-12T18:47:48Z")
And if the cop car can’t catch you, there’s always the sidewinder missiles… ---
**Author:** ![BF](https://avatars.discourse-cdn.com/v4/letter/b/b5ac83/32.png) [@BF](https://boards.straightdope.com/u/BF)\ **Post date:** [August 12, 2002, 7:09pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/4 "2002-08-12T19:09:57Z")
[Here’s a pretty good explanation of VASCAR.](http://travel.3dresearch.com/prep1.html) ---
**Author:** ![JohnM](https://avatars.discourse-cdn.com/v4/letter/j/848f3c/32.png) [@JohnM](https://boards.straightdope.com/u/JohnM)\ **Post date:** [August 12, 2002, 8:01pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/5 "2002-08-12T20:01:55Z")
One of my sisters-in-law tells a story of how she once got out of a speeding ticket. I understand that such stories fall into the same category of generally exaggerated tales as fishing stories, so take it with a grain or more of salt. Anyway, she was driving on an interstate in Iowa, and approaching drivers flashed their lights. She slowed down, and then came over a small rise to see a state trooper flagging her down. After she pulled over, the following dialog occurred: Trooper: The officer in the aircraft clocked you at 95 MPH in a 55 MPH zone. I’m going to have to write you a ticket. Sister-in-law: I’m sorry, you can’t do that. T: Excuse me? S: According to Iowa state law, the officer observing the infraction must be the one who writes out the citation. I’ll be happy to wait here while the aircraft lands so that the proper officer can write the citation. T: Wait here. (Returns to cruiser, talks on radio, comes back). I’m going to let you go this time, but slow it down! S: Yes, officer. She was bluffing. He presumably radioed back to HQ, and nobody there knew whether such a law existed either. ---
**Author:** ![shulmahn](https://avatars.discourse-cdn.com/v4/letter/s/6bbea6/32.png) [@shulmahn](https://boards.straightdope.com/u/shulmahn)\ **Post date:** [August 13, 2002, 1:41am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/6 "2002-08-13T01:41:40Z")
You know the first time I saw that sign “Speed limit enforced by VASCAR” I thought it actually said NASCAR. Hell, I was driving in Virginia… so I thought it was totally possible to see Jeff Gordon tailing me or something… just wanted to share 🙂 ---
**Author:** ![Ringo](https://avatars.discourse-cdn.com/v4/letter/r/779978/32.png) [@Ringo](https://boards.straightdope.com/u/Ringo)\ **Post date:** [August 13, 2002, 1:51am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/7 "2002-08-13T01:51:11Z")
> [@](#): > > …I thought it actually said NASCAR. Officer, “Hey, pick it up there, buddy! Whaddya think this is, a school zone?” ---
**Author:** ![AWB](https://avatars.discourse-cdn.com/v4/letter/a/bb73d2/32.png) [@AWB](https://boards.straightdope.com/u/AWB)\ **Post date:** [August 13, 2002, 2:11am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/8 "2002-08-13T02:11:49Z")
When I was little, the main street in my town had this sign up and down its length. I thought it meant that an airplane would swoop down and bonk the top of our car until we slowed down. :D:D:D:D ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [August 13, 2002, 2:30am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/9 "2002-08-13T02:30:00Z")
Hrmm, I call UL on that SIL story. ---
**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:** [August 13, 2002, 3:03am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/10 "2002-08-13T03:03:32Z")
So, given that VASCAR is unreliable and inaccurate unless the cop has stupendous reflexes, what do you think the odds are that I can beat a speeding ticket for 63.3 MPH in a 40 zone when I was timed for 2.28 seconds? I really, really, REALLY don’t want to pay it. Even though I was speeding. 🙂 ---
**Author:** ![happyheathen](https://avatars.discourse-cdn.com/v4/letter/h/b5e925/32.png) [@happyheathen](https://boards.straightdope.com/u/happyheathen)\ **Post date:** [August 13, 2002, 3:56am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/11 "2002-08-13T03:56:42Z")
pay it. the expert witnesses (web sites generally don’t count) would be much more expensive. or - general method - demand (if allowed in your jurisdiction) a jury trial - the prosecution _hates_ that. [sub] **IOW -pay it** [/sub] ---
**Author:** ![JohnM](https://avatars.discourse-cdn.com/v4/letter/j/848f3c/32.png) [@JohnM](https://boards.straightdope.com/u/JohnM)\ **Post date:** [August 13, 2002, 4:22am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/12 "2002-08-13T04:22:25Z")
**Telemark** , I am somewhat doubtful myself, which is why I recommended taking the story with some quantity of NaCl. ---
**Author:** ![JohnM](https://avatars.discourse-cdn.com/v4/letter/j/848f3c/32.png) [@JohnM](https://boards.straightdope.com/u/JohnM)\ **Post date:** [August 13, 2002, 4:30am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/13 "2002-08-13T04:30:02Z")
**Telemark** , I am somewhat doubtful myself, which is why I recommended taking the story with some quantity of NaCl. ---
**Author:** ![JohnM](https://avatars.discourse-cdn.com/v4/letter/j/848f3c/32.png) [@JohnM](https://boards.straightdope.com/u/JohnM)\ **Post date:** [August 13, 2002, 4:32am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/14 "2002-08-13T04:32:37Z")
Argh, my first double post. Mea culpa. ---
**Author:** ![postcards](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@postcards](https://boards.straightdope.com/u/postcards)\ **Post date:** [August 14, 2002, 8:22pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/15 "2002-08-14T20:22:58Z")
In New York, it’s quite common to get hit with the radar gun by one cop, and pulled over further down the road and ticketed by another. The SIL story is BS. ---
**Author:** ![UncleBill](https://avatars.discourse-cdn.com/v4/letter/u/d26b3c/32.png) [@UncleBill](https://boards.straightdope.com/u/UncleBill)\ **Post date:** [August 14, 2002, 9:34pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/16 "2002-08-14T21:34:29Z")
> [@](#): > > \*Originally posted by Airman Doors, USAF \* > \*\*So, given that VASCAR is unreliable and inaccurate unless the cop has stupendous reflexes, what do you think the odds are that I can beat a speeding ticket for 63.3 MPH in a 40 zone when I was timed for 2.28 seconds? > > I really, really, REALLY don’t want to pay it. Even though I was speeding. 🙂 \*\* A quick calculation gives me a length of 212 feet timed at 2.28 seconds gives 63.4 mph. Keeping the distance the same, lets see 2.1 sec = 68.8mph 2.2 sec = 65.7mph 2.3 sec = 62.8mph 2.4 sec = 60.2mph you’d need to be at 3.6 sec to be at the speed limit. He wasn’t **that** sloppy. ---
**Author:** ![reidbader](https://avatars.discourse-cdn.com/v4/letter/r/b38774/32.png) [@reidbader](https://boards.straightdope.com/u/reidbader)\ **Post date:** [August 14, 2002, 11:20pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/17 "2002-08-14T23:20:34Z")
The Sister In Law story is not BS. In Texas this is the law too. The officer who saw you committ the traffic crime has to write you the ticket. ---
**Author:** ![Bearflag70](https://avatars.discourse-cdn.com/v4/letter/b/8e7dd6/32.png) [@Bearflag70](https://boards.straightdope.com/u/Bearflag70)\ **Post date:** [August 14, 2002, 11:26pm UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/18 "2002-08-14T23:26:59Z")
> [@](#): > > \*Originally posted by reidbader \* > \*\*The Sister In Law story is not BS. In Texas this is the law too. The officer who saw you committ the traffic crime has to write you the ticket. \*\* Gotta cite there, good buddy? I’m curious about this. Maybe the radio call from one cop to another is indadmissible hearsay throwing a monkeywrench into the prosecution’s case??? ---
**Author:** ![fluiddruid](https://avatars.discourse-cdn.com/v4/letter/f/c2a13f/32.png) [@fluiddruid](https://boards.straightdope.com/u/fluiddruid)\ **Post date:** [August 15, 2002, 1:06am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/19 "2002-08-15T01:06:46Z")
I’m in Iowa, and if there’s such a law, I’ve never heard of it. Officers running radar (without aircraft) often work in teams. ---
**Author:** ![dantheman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dantheman/32/9421_2.png) [@dantheman](https://boards.straightdope.com/u/dantheman)\ **Post date:** [August 15, 2002, 2:00am UTC](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575/20 "2002-08-15T02:00:56Z")
They should let you because the signs are poorly worded. I mean really. The aircraft isn’t **enforcing** a speed limit. That would mean that if you went 61 in a 60, the plane would shoot at you to slow your ass down. Ha! Just let em try it. I drive a Saturn. Oh, yeah. [Next page](https://boards.straightdope.com/t/speed-limit-enforced-by-aircraft/123575.md?page=2)