Washington Finds Computer Simulation Unreliable

Toadpipe writes "Washington State Court of Appeals reverses a conviction in which a computer simulation had been the main evidence. Quoting 'At issue was PC-Crash, a computer program distributed by Vancouver, B.C.-based MacInnis Engineering Associates. The program recreates traffic collisions using simulations and reconstructions. "PC-Crash had not been validated for the purpose for which the evidence was offered, simulation and prediction of multiple-occupant movement within a vehicle during a multiple-collision accident," the Court of Appeals said in ordering a new trial. "There is no general acceptance in the relevant scientific community of the use of the PC-Crash program for the purposes to which it was put."' Here is the Court's opinion."

Comments

not unreliable, but...

[Anonymous Coward]

uncertified.

Anyone can say that they're an expert. The court system requires that if you're going to present evidence, you better have some credentials. This program, apparently, did not have the proper credentials.

Duh

[mboverload]

Vehicle crashes are way more complex than anything we could currently think of.

Every part on a car would need to be tested for strength, width, height, depth, shape, mass, the connections holding it to another part, and that bolt tested...You get the idea. You would also need the conditions that happened the second the crash occured. Road type, amount of friction, temperature, slope, etc. As a juror I would never trust a computer simulation.

Re:Duh

[Evil Adrian]

Hello... how do you think cars, airplanes, etc. are engineered? They simulate this kind of data all the time...

Re:Duh

[mboverload]

Yes, in a controlled enviroment with all variables accounted for and the actual blueprint of object.

Re:Duh

[mboverload]

You are right, they can semi-trust it to give an idea of what happened (Car A hits Car B directly on side, moves Car A 10-30 feet). This is not good enough for a court case. Take the "lie detector" for example. Even if it was way more accurate than it is currently courts would still not allow it into evidence.

Re:Duh

[LetterRip]

[QUOTE]Every part on a car would need to be tested for strength, width, height, depth, shape, mass, the connections holding it to another part, and that bolt tested...You get the idea. You would also need the conditions that happened the second the crash occured. Road type, amount of friction, temperature, slope, etc. As a juror I would never trust a computer simulation.[/QUOTE]

This is like claiming that we can't calculate the acceleartion on an apple due to gravity, because the actual effect of gravity is dependent on the gravitational force of every atom, etc.

Perfect knowledge is not necessary to acquire a reasonably accuarate simulation or estimation. And the error bars on simulation can easily be small enough that they are irrelevant to the conclusion.

Now, we don't know the particular of this case, but nowhere near the information you seem to think is neccessary is actually relevent to a reasonably and usefully accurate simulation.

LetterRip

Re:Duh

[foog]

How do you think cars and airplanes were engineered before we had crummy, inaccurate computer simulations?

In the real world, when being right is more important than having a merely plausible prediction in vibrant colors, people do experiments and laboratory tests.

Simulations by experienced analysts often turn out wrong: data from crash tests is much more trustworthy than the best simulations, let alone simulations performed by cops or prosecutors with some two-bit PC software.

I actually read the article

[tsstahl]

I know, I may have to turn in my /. account.

I would like to see more of this kind of common sense in life today.

The story states both occupants were ejected from the car in the accident. The prosecution is quoted as saying their key element of the case was that part of the passenger door was melted on the dead guy.

So which was it? Did the dead guy stay there and take the burn, or get ejected? Did the car sit for awhile burning, and take off again?

I will make the specific conclusion from the vast amount of data in the article that there was enough doubt to go around in this case.

/sarcasm off

To often attorneys for both sides put up a George Lucas light show in order to sell their version to a jury. Matters are not helped by the fact that jury selection all to often resembles a Jerry Springer casting call.

I've seen the software in question used in a trial (once). What I saw seemed to be a believable representation of an elastic collision between vehicles. At no time were there any renderings, or mention of what happened INSIDE the vehicles. But then again, you know what they say about prepared demos...

Not validated != Unreliable

[HardCase]

Even the summary belies the headline (and the article torpedoes it). The conviction was overturned because the software was not validated for the use for which it was used. The court made no comment on its reliability...they left that up to the scientific and engineering community. Based solely upon the court's comments and the article, it sounds like a good decision to me.

=h=

Teaching to the test

[coyote-san]

I have a more general problem with red-light radar (and most red-light radar) - it's "teaching to the test." Or in this case, "enforcing laws that are easily mechanized, not laws that are most critical to public safety."

The biggest problem I face on the road are tailgaters and the guys who cut me off at interstate speeds and the morons who barrel out of parking lots at 20 mph without checking for traffic and the idiots who think "right turn on red" has right of way over people already on the road. Hell, even the superjock riding his bike far too fast for me to see him approaching as I cross the bike path... and he wrongly believes that he, not I, have right of way. (Pedestrians do, but in this state mounted bikes are "vehicles" and bike paths are "secondary roads.") As if it will matter when he hits my car (or vice versa), other than me suing his estate to repair my car's paint job.

People who run red lights or are speeding between lights on limited access roads? Not A Problem. Maybe once every few years I'll nearly get clobbered by some moron who goes through an intersection at high speed long after the light changed, but that's reckless driving, not merely running a red light. The latter should remain illegal, but a low enforcement priority unless it's an ongoing serious problem at a specific location.

So why do we see more and more red-light X systems? Because they're cheap revenue sources. To actually make driving safer you have to hire more cops and put them in more unmarked cars and get them out on the street where they can nail the guys who really are hazards to other drivers. Not guys going 45 in a 35 zone because that's what the heavy traffic is doing and it would be far more dangerous to obey the law than to break it. Or the guy who's behind a truck and doesn't know the light has turned red until he's already in the intersection.

How long until the laws themselves are written on the basis of what's easily enforceable, not on the basis of what harms others?

And the guy in Denver who put a photo-radar system on the interstate onramp where traffic is always at least 15 mph over the posted speed limit? The cop who lectured my HS class wants to talk to you - he assured tens of thousands of us that no cop would ever, under any circumstances, ticket us for going over the speed limit in order to merge with traffic. (We were supposed to gradually slow down once merged.) Ticket or being flattened by a semi? Hmm, which will it be? Ticket or being flattened by a semi. Gee, that's such a hard decision. Not.

Re:Teaching to the test

[martinoforum]

"People who run red lights or are speeding between lights on limited access roads? Not A Problem. Maybe once every few years I'll nearly get clobbered by some moron who goes through an intersection at high speed long after the light changed, but that's reckless driving, not merely running a red light. The latter should remain illegal, but a low enforcement priority unless it's an ongoing serious problem at a specific location."

Red light running is potentially lethal, moreso than tailgating in many situations. I get tailgated on a daily basis and have yet to be rear-ended (although it's a major annoyance), but the two times I've had somebody run a light as I was pulling out into an intersection where the approach for the other road wasn't visible has nearly killed me. Seriously, having somebody rocket past the front of your car at 90kph as you pull across the intersection is fucking terrifying. You can avoid it a little if you can actually see the road both ways from your position at the intersection, but there's a few around here where the crossing road is blind in the direction that traffic comes from - in one case, it's an off-ramp for a motorway where dumb drivers come off at 100kph then ACCELLERATE DOWNHILL in an attempt to make the lights. Needless to say there's a lot of accidents there due to retards armed with a drivers licence.

Long live red light cameras. If the light is green, I have a reasonable expectation that nobody is going to ram into the side of me. If you can mechanically fine the crap out of anybody who is regularly violating that one then go for it.

Tailgaiting is an admittedly associated problem though, as it's hard to stop a car abruptly at an orange light when there's some dickhead 50cm from your back bumper. But over here at least, if you can present a photograph showing somebody that far from the back of your car when you get snapped then you stand a good chance of disputing any fines by writing into the police and stating your case.

Re:Digital evidence

[TWX]

Who's the victim?

Do you exceed the posted speed limit?

What defines it as a crime when it hasn't yet been through due process?

It's the job of the constabulary to enforce laws in person to protect the public, and to investigate real crime that has already occurred. Photo Radar for speed enforcement is a stupid idea, and just leads to people finding out where the cameras are that day, speeding everywhere except by the cameras. Traffic used to even require an officer to serve one with a court notice (the traffic citation), same as an officer picking up a wanted criminal to force a court appearance. Many cities don't even use the police departments to run photo radar, they contract it out to companies, who give the city a portion of the money collected. One such company is American Traffic Systems, who has operated in Scottsdale AZ and San Diego CA if memory serves.

By not receiving instant citation, the accused has no opportunity to place any importance on the memories that might help them form a defense. The prosecution/plaintiff is rarely forced to appear in court either, let alone testify to remembering the vehicle as it sped by, or any of that, like a real officer is required to do. A real officer is required to take an oath that he or she isn't committing perjury when they testify. A picture sent to the court isn't, and should be thrown out if the prosecution/plaintiff does not appear to press their side.

Photo Radar is treating people as guilty by default, without requiring individual explanation, or without an arraignment, pre-trial conference, and trial. It's a travesty to justice and a continual erosion of the rights of citizens by the government.

Shishberg Finds Article Title Unreliable

[Shishberg]

In related news, the Slashdot community have dismissed the post's title - "Washington Finds Computer Simulation Unreliable" - as being inconsistent with the article, or indeed even the summary of the article directly beneath the title.

At issue was the word "Unreliable", which implies some comment on the accuracy of the software in question. The article, however, consistently states that the software "had not been validated for the purpose for which the evidence was offered", a far more sensible claim.

"Titles of Slashdot posts have not been validated for the purpose for which this one was offered, simulation and prediction of the content of the article itself," a Slashdot representative stated. "There is no general acceptance in the relevant online community of the use of article titles as a substitute for R-ing TFA."

CowboyNeal was not available for comment.

Re:Darn it

[caveat]

X-Plane is usable for instrument, commercial, and airline pilot cert training (linky). Of course, "actually LOGGING this time requires you to be in a Motus full-motion sim (price tag: about $150,000.00) with an instructor" - but still, MSFS isn't rated for jack shit. It's just a game.