ABSTRACT
In the second simulation experiment, we investigated the effectiveness of presenting lane departure warnings in three modalities-visual, auditory and tactile. The 55 participants were 24 snowplow operators, 17 state patrol troopers, and 14 ambulance drivers. This time the visibility was 90 meters and the roadway was completely snow-covered-so that, effectively, the participants were driving in whiteout conditions. Without exception, when the 55 participants drove without using the DAS, none of them could stay on the road-even driving as slow as 5 mph (8.05 km/h). In contrast, when they did use the DAS, they were able to drive at normal speeds. As a result of this experiment, we recommended that lane departure warnings should be presented in all three modalities simultaneously
Following the simulation experiments, we conducted a field test, with 13 snowplow operators driving a snowplow that was fully equipped with the DAS on a 4.5-mile (7.2-km) long closed track (Bloomfield and Harder, in press). The field test was conducted after the first snows of the 2000-2001 winter, in temperatures that varied between 30 deg F (minus 1 deg C) and minus 18 deg F (minus 28 deg C)—consequently, a mixture of ice and snow covered the course throughout the test.
