Citation

Zwahlen HT, Schnell T, Hagiwara T. Transp. Res. Rec. 1995; 1495: 87-98.

Copyright

(Copyright © 1995, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Pavement markings on public roads provide driver guidance, convey advisory or warning information to the driver, or both, and are often used as a supplement to other traffic control devices without redirecting the focus of attention from the road. Adequate visibility of pavement markings at night is an important element of driver safety, especially in the absence of public lighting. Increased lateral separation between double center stripes could increase the detection distance because the human visual system would spatially integrate over the lateral space between the parallel lines to form a more visible target that subtends a greater visual angle. Most of the technical literature has shown that there seems to be no available pavement marking visibility data on begin-and-end detection distances. Also, no data are available on the effects of lateral separation between double solid center stripes and the interaction between lateral separation and line width. The current study was conducted to provide a scientific basis for quantifying the effects of lateral separation between double solid center stripes. It is current standard practice in Ohio to implement double solid yellow center stripes (0.1 m wide) with a lateral separation of 0.1 m. On the basis of a field experiment involving 48 subjects, average begin-and-end detection distances were established and psychometric curves were plotted. An ANOVA and Scheffe post hoc test failed to find any significant systematic effect caused by lateral separation between the center lines. On the basis of the findings of this study it is possible to tentatively conclude that an increase in the lateral separation (from 0.05 to 0.2 m) between the double center stripes does not appear to be a useful method to increase driver visibility. In addition, as expected, the amount of retroreflective material (0.05, 0.1, 0.15, or 0.2 m width, double solid versus dashed, gap/stripe ratio of 9.15/3.05 m versus 10.98/1.22 m) has a fairly small effect on the 85th percentile end detection distances, thus indicating a relatively small marginal gain in visibility with a substantially increased retroreflective area. In fact, calculations indicate that an increase in area from 0.122 to 2.44 sq m for each 12.2-m-long center line segment (20-fold increase) is required to increase the average end detection distance from 82 to 128 m, which in only an increase of 56%.

Record URL:
http://onlinepubs.trb.org/Onlinepubs/trr/1995/1495/1495-011.pdf

Language: en

Keywords

Automobile drivers; Traffic signs; Visibility; Pavements; Highway traffic control; Statistical methods