Citation

Stoughton RL, Parks DM, Stoker JR, Nordlin EF. Transp. Res. Rec. 1979; 703: 24-30.

Copyright

(Copyright © 1979, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

The effect of edge of pavement drop-offs on vehicle stability is reported for 50 tests of professional drivers handling small-, medium-, and large-sized automobiles and pickup trucks off, along, and back onto drop-off heights of 38 mm (1.5 in), 89 mm (3.5 in), and 114 mm (4.5 in) at about 26.8 m/s (60 mph). Tests of two- and four-wheel drop-offs were conducted from an existing asphalt concrete shoulder onto both compacted soil and asphalt concrete surfaces. The drop-off heights had little effect on vehicle stability: steering wheel angles were generally 60 deg or less; vehicle roll angles were 10 deg or less. A significant jolt and accompanying frontend noise were experienced by the driver at the larger drop-off heights; there were no problems with vehicle alignment. Less than one wheel revolution was required for the first wheel to mount the drop-off heights. Varying amounts of front-wheel wobble caused mainly by an irregular drop-off edge were detected. There was virtually no deviation in vehicle trajectory as the vehicles remounted the drop-off edges, and the vehicles did not encroach into adjacent traffic lanes. Two nonprofessional drivers participated in a few supplementary tests. They had no difficulties driving over all three drop-off heights at 17.9-20.1 m/s (40-45 mph). The results of these tests were used to help evaluate the California maintenance standards in effect in 1974.