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

Digital evidence

[TWX]

I'd like them to stop accepting photo radar data. The cities in my area have switched to digital photography. Currently one's only out is to request the Plaintiff to produce the calibration records for the system for the day of the ticket and hope that they don't have that data.

I'd be okay with photo radar and with red light cameras if they were used to bolster the Prosecution/Plaintiff, like if there were a car accident and the red light camera data were used to show that the cited person (by the officer on the scene) had indeed run the light, and that the officer was correct. The current system of using photography with near-automatic conviction deprives people of privacy. If the police want to cite people for speeding or for any other traffic violation then they need to get out there with people who will be required to testify as to what they saw; people who actively claim the count in the charge, not some computer or desk-jockey who analyses data after the fact.

Of course, I also have the opinion that if there's no victim then there's no crime. Take this as you will.

Re:Duh

[EvilTwinSkippy]

You don't understand simulations.

When Ford, or Daimler Benz goes out to design a car, they know where every bolt, nut, rivet, weld, and cup holder are. That information is fed into a finite element analysis model that breaks the car down into ever finer blocks of deformable material.

They than take that model and bash it against a series of controlled obstructions.

Even then, those simulations are just used to rule out certain design changes. All final designes are bolted to a hydrolic ram, filled with test dummies, and shot into a wall or another vehicle.

And again.

And again.

Yes, the automaker DOES have a model of the car. Yes, that model could be fed into another FEA. But in order to produce any meaningful result you would have to have equally good data about all the occupants in the car. Where everything on the road was, and at which time in the "event."

And did I mention that the simulation is only as good as the least accurate measurement? At best. And most of the data you would have needed is gone as soon as rescue crews arrive and attempt to move the vehicles out of the way of traffic?