Effects of Size, Location, Contrast, Illumination, and Color on the Legibility of Numeric Speedometers

摘要

The study developed a formula to predict how long drivers take to read digital speedometers, a measure of legibility. A total of 18 drivers responded to instrument clusters and distant targets. Response times and errors were recorded for over 52,000 slides. The size, location, and contrast of the digits and the illumination level varied across 3 days of testing. The effect of chrominance (Delta E,) was tested on a fourth day. Each unit increase in Delta E (between 90 to 106) resulted in a 2.1 ms decrease in response time.