ITD studying whether thinner (or thicker) stripes improve driver safety

The Idaho Transportation Department is studying the correlation between the width of highway stripes and the visibility for drivers, to potentially improve the safety of motorists on Gem State roads. A three-year study is underway in north-central Idaho between ITD and the University of Idaho to do just that.

“We are looking at the line width to see if it increases visibility for drivers, particularly older drivers,” explained ITD north-central Idaho Traffic Engineer Jared Hopkins.  “We may be able to positively impact safety, and that’s what the research is all about.”

The standard width of a highway stripe is four inches, but varying widths from two to six inches were used in a driving simulator (pictured above) starting in early 2015 to test “run-off-road” crashes, which are extremely common in Idaho. Four-inch stripes are also being compared to six-inch stripes in real-world applications on various stretches of highways in the region. The durability of the paint at varying widths is also being tested in the $174,000 research contract.

The research project for the stripe width will be completed in the first part of 2018.

If the thinner stripe proves adequate in a field test (right now it is only being tested in the simulator), this could save the department significantly in the cost required to paint stripes on the highway.

Published 03-04-16