If we choose to proceed with full knowledge of a hazard, we assume at least some risk. If the hazard has been knowingly or carelessly disguised, an accident can be expected. A man visiting a public park broke his leg in a fall as he tried to descend three wooden steps to a lower level. His foot had slipped on a defect in the leading edge of a step. The public parks department investigated the accident and painted the steps with a bright orange paint to call attention to the stairs.
Lighting can disguise a defect or hazardous condition.
A change in the normal walking environment must be visible to the pedestrian and stand out from background stimuli. The walking surface should be evenly illuminated and should have a brightness level of at least 20 foot candles - a basic quantitative unit of light measurement. The measurement of luminosity and contrast requires a simple photographic light meter calibrated to read in foot candles. Photographs of the accident scene can help the investigator evaluate the effect of light on the mishap. It is important to photograph the site properly, making sure the photographs represent the accident point from the eight compass positions.