It depends what you do in the laboratory.

Late in the year 1999 one of us (RJW) was asked to provide expert witness evidence to a Public Inquiry that followed a fatal train crash in London (Cullen, 2001). The fundamental question was whether there was any good perceptual explanation for a driver proceeding through a red signal when on so many other occasions he and other drivers had not got it wrong. To cut short a long story, it was found that some 5 or 6 seconds away from the signal, it would have appeared to be yellow not red for a brief moment because of a combination of optical and visual factors. However, no-one was able to explain why in the remaining time beyond that brief moment, when the signal should have reverted to appearing red, the driver didn't notice that the signal was in fact red. Although the driver would have had no reason to look at the signal again, five seconds is a long time.