Search Results

This paper presents results of revisions to the DETECT model made to include the effects of driver age on visual performance in night driving. This paper will present age related changes made to the subprograms that compute: the visual contrast thresholds, disability glare effects and discomfort glare index. Outputs of runs are presented which illustrate functional relationships of driver age to pedestrian seeing distance and discomfort glare experienced by drivers.

A Headlight Evaluation Model has been developed which provides a broader and more comprehensive method for characterizing the performance of headlamps than is possible in traditional headlight seeing distance field tests. The Headlamp Evaluation Model accepts as input the candlepower patterns of the headlamp system being evaluated and provides a measure of driver visual performance based on a large number of simulated seeing distance tests and glare discomfort checks on a standardized test route. The output of the Model, termed the Figure of Merit, is the percentage of the distance traveled by the simulated driver on the standardized test route in which the seeing distance to pedestrians and pavement lines, and the discomfort glare levels experienced by opposing drivers, simultaneously meet certain acceptance criteria.

This study assesses the understanding and recognition, by U.S. drivers, of the 25 automotive ISO symbols specified in SAE Standard J1048. A two-part survey was administered to 505 volunteers at a Secretary of State's office located in a Detroit suburb. Percentage results for symbol understanding indicated low levels of understanding for many symbols; percentage results for symbol recognition were generally much higher for all symbols. The effects of gender, age, and education level on the percentage results are summarized.

This study assesses the understanding and recognition, by U.S. drivers, of the 25 automotive ISO symbols specified in SAE Standard J1048. A two-part survey was administered to 505 volunteers at a Secretary of State's office located in a Detroit suburb. Percentage results for symbol understanding indicated low levels of understanding for many symbols; percentage results for symbol recognition were generally much higher for all symbols. The effects of gender, age, and education level on the percentage results are summarized.

Analyses were performed to determine the sensitivity of stopping sight distance on vertical curves to driver eye height and other parameters entering into the stopping sight-distance equations. Sight distance was found to be relatively insensitive to eye height. On a given hill crest, sight distance for a driver whose eye height is 6-inches lower than the design eye height (3.75 ft) is only 5% less than the design sight distance. On the other hand, stopping distance is very sensitive to travel speed, pavement friction and reaction time. For example, a 1.8 mph decrease in speed reduces stopping distance by the same amount that a 6-inch decrease in eye height reduces sight distance. Also, sight distance is about 2.5 times more sensitive to obstacle height than eye height. It is argued that reductions in travel speed since the introduction of the 55-mph speed limit compensate for any recent or projected decreases in driver eye height.