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Driver Eye Height and Sight Distance on Vertical Curves
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English
Abstract
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. In addition, because the hazard posed by a 6-inch high obstacle is dubious, it is suggested that vertical curves designed for that obstacle height probably incorporate a considerable safety factor.
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Authors
Citation
Farber, E., "Driver Eye Height and Sight Distance on Vertical Curves," SAE Technical Paper 811286, 1981, https://doi.org/10.4271/811286.Also In
References
- Anderson, H. L. “Incompatability Between Highways, Vehicles and Drivers,” Proceedings of the American Association for Automotive Medicine, October 1980
- Stapleton, J. J. “Tort Liability Implications of Small Car Incompatability with Highway Design,” Proceedings of the American Association for Automotive Medicine, October 1980
- Boyd, M. W. Littleton, A. C. Boenau, R. E. Pilkington, G. B. “Determination of Motor Vehicle Eye Height for Highway Design,” FHWA-RD-78-66, Federal Highway Administration, April 1978
- Pilkington, G. B. “Decision Sight Distance Requirements for the Small Car Driver,” Presented to the Annual Congress of the SAE 1979
- “A Policy on the Geometric Design of Rural Highways — 1965,” 1966
- Lee, R. L. Scott, C. P. “Driver Eye Height and Vehicle Sales Trends,” Federal Highway Administration, Office of Highway Safety, Effectiveness Evaluation Branch, January 1981