Physicist Uses Math to Beat Traffic Ticket

http://www.physicscentral.com/buzz/blog/index.cfm?postid=4656335810518469535

by bhavin • 14 years ago

106 71 14 years ago

bcl• 14 years ago

A friend of mine beat a speeding ticket once by demonstrating that it was physically impossible for him to have slowed down from the claimed speed and stopped in the location where the officer wrote the ticket.

lotharbot• 14 years ago

A guy from my parents' church beat a speeding ticket by demonstrating that the motorcycle cop would have had to reach a speed of over 160 mph in order to clock him at the speed measured at location A and then catch him by location B.

jaylevitt• 14 years ago

I once failed to beat a speeding ticket by not noticing that the officer had forgot to introduce the ticket into evidence. I introduced it, the judge said "Really? Are you sure?", I missed the hint, and since a ticket is evidence of speeding in Massachusetts, my case was kinda shot...

sosuke• 14 years ago

The paper was submitted April 1st according to http://arxiv.org/abs/1204.0162

April fools perhaps?

whackberry3• 14 years ago

Does look like so. No judge I know would spend even 5 minutes on a misdemeanor case such as this one.

drucken• 14 years ago

Haha, nice way to beat the system. But I doubt the symmetry of those two graphs.

Surely, there is no (ordinary) retail car on the planet which can accelerate as fast as it decelerates?

ktizo• 14 years ago

I doubt there is any car that can unless the brakes are really dodgy (apart from the rocket powered ones with parachutes)..

Just goes to show, if you haven't got a hope in hell, try bullshit and long words.

[edit] Just looked up formula one cars, they are 2g acceleration and 5g braking apparently.

tedmiston• 14 years ago

First comment: "venky said...

He claims in his model, 'his car decelerated at - 10 m/s^2 and, instantaneously, accelerated to + 10 m/s^2 at t = 0'.

No known mechanical system is capable of achieving such an instantaneous jump without a tail-off period. ...."

xxbondsxx4• 14 years ago

MechE here, electrical motors can obtain almost instantaneous acceleration / full torque at 0rpm. Their torque curves typically look like this:

http://www.jmag-international.com/catalog/img/e68-3b.gif

The brakes are independent, so it's not as if one system has to provide both accelerations, one just needs exceptional timing of the feet. A lot of rally car drivers can do similar maneuvers

This is the same reason why the Tesla Roadster has such a killer 0-40mph

mistercow• 14 years ago

First, we assume a spherical car...

RegEx• 14 years ago

Ah, the perfect physics world. It's a fun place to go from time to time.

excuse-me• 14 years ago

A modern hatchback (VW Golf) with good tires on a perfect road can decelerate at 1g with a pro driver. In tests regular drivers posted between 0.9 - 0.6g in a range of cars from Ferrari to Honda civic.

To do 1g in acceleration you would need to do 0-60 in 2.75s that MIGHT be possible for a $1M supercar (or a bike ;-)

joshu4• 14 years ago

I think a GT-R can do that. It's certainly close.

cellularmitosis2• 14 years ago

The Ariel Atom can do that in 2.9 seconds for about $60k USD. On a scatter plot of acceleration vs sticker price, the Atom is a true outlier.

http://m.youtube.com/watch?v=6v4YNkurhLk

The only point on that plot which would be even more of an outlier would be a shifter-kart.

loverobots• 14 years ago

But then the prosecution would have to bring it's own expert witness...over a traffic ticket.

xxbondsxx4• 14 years ago

MechE here, the limiting factor for car accelerations is usually the static coefficient of friction between the car tires and the road, _not_ the power of the brakes or strength of the engine.

Without ABS braking, it is quite easy to "skid" while applying a harsh brake because you overcome the limit of force between the tires and the road. Similarly, it is quite easy to "burnout" as well with a strong engine for the same reason.

So although the strength of the two systems is not the same, the limiting factor for both of them is identical. Hence, symmetry.

shasta• 14 years ago

Car owner here. I don't think this is right.

_ea1k• 14 years ago

The limiting factor on acceleration in the Toyota Yaris is ont the tires.

cellularmitosis2• 14 years ago

This is true for the deceleration side of things (nearly any car can lock it's brakes at any speed), but on the acceleration side of the curve, this is typically only true in first, and perhaps second gear. It would take a truly obscene amount of power to smoke the tires while already in 5th gear (assuming you dont "cheat" by popping the clutch).

dmd2• 14 years ago

> or maybe he was simply impressed by the sheer dedication Krioukov put into avoiding this ticket.

This seems more likely.

I beat a speeding ticket with GPS data once - except the judge didn't even ask to see the data. I just said I had it. (Yes, the officer was there in court too.) The judge said he'd take my word for it.

0bs1di4n• 14 years ago

My friend always appears in court after getting speeding tickets because it is apparently more costly for the court to pay for the session and the officer's time than what they will get from a ticket, so they usually dismiss it to save money. Sometimes the officers don't even show up. He has told me it works every time.

grannyg00se• 14 years ago

If everybody would choose to appear in court like your friend does, perhaps this law that most people don't follow would actually get changed. Instead most people just pay the ticket and continue to allow the law to "work" as it is.

kelnos• 14 years ago

If you lose in court, though, aren't you required to pay the cost of the session? (I have no idea, never done it before, just curious.)

arantius• 14 years ago

And what is your own time worth?

huhtenberg• 14 years ago

> I want to ask the readership to please find the flaw in the argument.

"The officer had special two-week training that qualifies him to estimate angular velocity whichever the fucking way he wants, even with a completely obstructed view."

Courtesy of Canadian reality. Plot me a graph to counter that.

mynegation• 14 years ago

Right, so I do not know about California, but in Canada if at stop sign the back of your car did not have a chance to come full way down on suspension, the stop is not considered to be performed properly. His charts assume instantaneous change in acceleration let alone any "settle down" period.

joshmlewis4• 14 years ago

Yeah, that took some dedication, and because we aren't all as dedicated or physicist here are some practical tips I've learned:

1. When an officer asks how fast you were going, never say anything over the speed limit or that's automatic guilt. Just decline to know or tell. A lot of people say within a +5-10mph range over the speed limit because they think that is "ok", but in fact anything over the speed limit is speeding and is ticket worthy.

2. Look up laws in your area about loopholes. I once had a friend who got pulled over for doing a burn out in his Cobra, the officer was so aggravated he forgot to wear his hat when he got out of his car and the case got dismissed because of it.

3. Always be polite. Always, always, always. Even if they're real jerks, which has never happened to me, always be courteous and make things go as smoothly as possible. If you start being an ass they WILL remember it and will take that into consideration when writing the ticket and/or in front of the judge. You'll have a chance to give your side in court, so don't bother wasting your breath with the officer.

4. I once got out of a reckless driving ticket ($400+, I was young and dumb) because I just happened to know the director of the area highway patrol. It turned out I was in the top 5 worst tickets the highway patrolman had ever given out in his 20+ years of duty. My director friend told him I was a good kid and my parents were going to kill me anyway, so he let me off.

5. And really, the single most best way to not get a ticket, don't break the rules. Of course in this guys case the officer apparently was mistaken, but more times than not that's not the case.

This got large quickly. Just some things I've learned over a few years of driving.

culturestate• 14 years ago

> in fact anything over the speed limit is speeding and is ticket worthy.

This actually varies per jurisdiction, though that's still a good general rule. In Florida, for example, you can't be ticketed for 1-4mph over the limit thanks to a law that was passed to eliminate speed traps.

cperciva2• 14 years ago

the officer was so aggravated he forgot to wear his hat when he got out of his car and the case got dismissed because of it

That really sounds like an urban myth.

AdamTReineke• 14 years ago

It's possible (though I haven't done any research) that the law may require a uniformed officer to make the stop and the hat is part of the uniform. No hat -> not uniformed -> not a legal stop.

joshmlewis4• 14 years ago

This is interesting actually. I kind of "took his word for it" and never put too much thought into it. After about 20+ minutes of Googling I have yet to find a definitive answer. I guess it just depends on jurisdiction. I'm not sure if I would have the guts to say, "Judge Officer here wasn't wearing his hat when he gave me this ticket." So I don't know, I read a few things that supported it and a few that didn't. I should ask my director friend if it's true. Ha

rdl3• 14 years ago

The #1 thing I do when stopped is go out of my way to 1) prioritize officer safety and 2) avoid generating probable cause for a vehicle search.

i.e. pull over in a place which is safe for both vehicles and for the officer on foot, keep hands visible all the time, turn on dome light, put keys on dashboard, and be polite. Also I tend to announce any moves, like "my wallet is in my back pocket, reaching for it with my left hand", which is overly cautious, but subtly communicates to the officer that you are familiar with police procedures and concerns. You can usually see him visibly relax, at which point it's likely the interaction will be more pleasant. Don't volunteer more information than necessary, but answer questions politely and clearly. (usually, it's just "license and registration." and then "do you know why I stopped you" "no officer"...)

I've gotten >120mph written at 80mph in a 70mph by doing this, several times (I-5 + V8 + empty road...), which can be traffic-schooled. I don't care about a $150 ticket, I care about potentially getting the car impounded for reckless driving, or a vehicle search, or points.

whackberry3• 14 years ago

> my wallet is in my back pocket, reaching for it with my left hand

If I were a officer and someone narrated what they're doing like that I'd immediately find it suspicious. Just say you're gonna get your wallet, cops aren't all completely stupid.

"I'm reaching for my wallet with my left hand sir" sounds retarded.

vacri5• 14 years ago

It may not always be a good idea, but for me, when I get pulled over, I get out of the car immediately. In my 20s I was pulled over so many times for 'random' car checks that were really about bored policemen passing time, that I started to get out of the car first to upset the dynamic.

It helps that I'm really tall, but it's worth it for the look on their face when it turns from 'bored paternalism' to 'we might have to watch what's going on here'; it takes some of the initiative from them. It's a subtle way to change the power dynamic, especially if you're tall - you can no longer be talked down to, plus you're free to move. Being free to move isn't about posing a physical threat, but being able to control your end of the conversation better, plus you can watch what they're doing. Of course you should always, always remain polite, but screw being in the entirely submissive position of being locked into your seat.

Incidentally, the 'random' checks have stopped in the past 5 years that I've had a newer car... and curiously my mother has never been 'randomly' stopped.

nopassrecover2• 14 years ago

Absolute worst idea. This counts as an act of escalation (it counts as a threat to police safety) and is likely to end up with a definite ticket and potentially a handcuffed trip to the station if you don't get back in your car fast when ordered.

Particularly if you're physically imposing you run the risk of a panicked officer pulling their weapon..

joshmlewis4• 14 years ago

Yeah, I agree with the above poster, horrible idea. Most cops in my experience aren't what the internet makes them out to be. They do their job because they want to serve and protect citizens and having to "change the power dynamic" and "avoid being talked down to" is just silly and jumping out of your car will put cops on edge very quickly. You don't want that. Most of the time they pull someone over it's because you've done something to look shady or you're actually breaking the law.

rhizome• 14 years ago

For #1: "Why were you going so fast?"

KingOfB• 14 years ago

Other Helpers:

- Use the most official title: 'Yes Trooper', 'Thank you sheriff', etc.

- Be honest, authentic and remorseful, but not apologetic. (I don't agree with #1)

- Be well groomed. After I got my beard and hair cut, I stopped getting tickets. I've gotten 8 consecutive warnings, most verbal. Before getting 'cleaned up', I got 9 tickets and 1 warning.

- Have a woman in the car. Doesn't have to say anything, just smile and reply to questions.

- Pull over, turn on the dome light and leave your hands on the steering wheel. I lower my window when a flashlight hits me, and only get paper work in response to a command.

My streak of warnings still dumbfounds me. I even got pulled over twice after a superbowl for a tail light and got a verbal warning twice.

joshmlewis4• 14 years ago

Yeah I didn't mean to be dishonest there. Honesty does help. But it also makes it an auto admission of guilt. Use discretion playing either card really in your situation.

Steko• 14 years ago

Recreation of the courtroom, from my brain:

Physicist: "Pretty much cold feet and sneezes your honor, QED."

Judge: "Well seeing as how you're a member of the affluent class I shall not inconvenience you further."

ww520• 14 years ago

I had a similar story. I once sped through a traffic intersection and a cop car coming from the other way perpendicular to my heading. He turned immediately and chased me down. After stopping, he ordered me out and said I was doing 110mph. I was like there's no fucking way I was doing 110. The car felt very different going 110 than 60. He was saying I looked like going very fast. The only thing that ran through my mind was to get a lawyer. Amazingly he left me go after lectured me for a while. I guessed he wasn't sure exactly how fast I went.

I was wondering how can he misjudge the speed so far apart. This article explained the phonomena.

codezero2• 14 years ago

Gets more love when it's a churched up article than when you just post directly to the PDF :(

http://news.ycombinator.com/item?id=3830019

m_for_monkey• 14 years ago

I give you a point, because that's what you really want, not "love" for the paper, right?

codezero2• 14 years ago

yes, of course.

throwaway1979• 14 years ago

I have a question about avg ticket costs. My first (and so far, only) ticket was in LA for crossing a solid HOV line. The ticket itself was 80-100. However, they added a ton of fees to it (the best one I remember was a fee for courthouse improvement but there were fees by the county of LA and the city of LA). All-in-all, the grand total was around 400. Is this just a California thing? I don't see how people can eat in that state when a ticket costs this much.

whackberry3• 14 years ago

It is amazing that a judge would even listen to this in a non-criminal and minor offense case. Most places I know it'd just be dismissed and the fine upheld.

gwern• 14 years ago

> "A way to fight your traffic tickets. The paper was awarded a special prize of $400 that the author did not have to pay to the state of California."

Good economics reasoning too - losing a loss is as good as gaining a gain.

eriktrautman• 14 years ago

His argument and charts imply a stopped duration of 0s. I was taught that a legal stop is >= 2 seconds duration. Guilty.

defen• 14 years ago

If you're in California, trial by written declaration[1] is a great way to deal with minor traffic violations. The way it works is that you fill out a form[2] giving your version of events, and submit a check for the amount of the ticket. The beauty of this is that the officer also has to fill out a form giving his version of events - and if he doesn't, you automatically win and your money is refunded. It's the equivalent of the officer not showing up to your court case. If he does submit the form you might still win if the judge sides with you. And if you lose, you can request another trial by written declaration. I'm 2/2 using this strategy for minor violations, and I haven't had to waste any time in traffic court. In both cases I won because the officer did not submit his version of events - probably because it's boring work and they had better things to do.

[1] http://www.dmv.ca.gov/pubs/vctop/d17/vc40902.htm

[2] http://www.courts.ca.gov/documents/tr205.pdf

michaelcampbell• 14 years ago

A buddy of mine tried the same thing (math in court) using the weight of his SUV, the HP of the engine, and other things to show he couldn't have been speeding at the location the officer said he was.

Result: "Too bad. Pay me."

Like they say in the movies; with law it's what is the truth, and what you can prove. He failed the latter and got a hefty fine.

nmridul• 14 years ago

Why is it that most comments here are about ways to fool a policeman and avoid a speeding ticket ? I was expecting more advices on reducing your speed and driving safely.

Physicist Uses Math to Beat Traffic Ticket

Related Stories