A vast number of persons can only understand things in black and white and this problem sometimes creeps into the justice system. The relativity of visibility is one of those issues where some believe that something is either visible or it is not. And whether something is visible is obvious, much like the flatness of the earth. The following is an example that can be used to reflect on more subtle scenarios.

The following photos show a work truck that is parked in the distant background on an arterial road in London, Ontario. Workers are busy planting trees on the boulevard and they have parked their well-marked and clearly visibility truck against the roadway curb. These photos were taken looking westward approximately 2 hours after sunrise.

The worker who is standing next to the driver’s door in the above photo is clearly visible.┬áIn contrast, the following photos were taken while approaching the truck eastward, or from the opposite direction to the photos above.

These westward photos were taken approximately 15 minutes before the eastbound photos. There are traffic cones near the rear wheels of the truck but these are very difficult to see. There are more traffic cones on the left side of the truck and these are readily visible because of the difference in contrast, not necessarily because the orange colour of the cones can be detected. And the content of the “Yield to Oncoming Traffic” sign is difficult to discern until the camera is fairly close to the rear of the truck.

Many persons hold the belief that unless the sun is very low on the horizon it is not an obstacle to most viewing situations. This black or white reasoning exists in many minds and works its way into official investigations and eventually into the reasoning of courtroom judgments. While experts and expert opinion is not immune to bias and misdirection it has the potential to reveal the subtilties of a collision scenario by revealing the hidden factors that might be play.