Traffic engineers in California began using orange pavement markings during construction to add carpool lanes on a four-mile segment of Interstate 5 north of San Diego. The striping is an attempt to cut down on accidents in work zones.
According to Route Fifty, the state transportation department is using the extra color to highlight the white and yellow lane markings while the highway is expanded. On one side of the highway, the orange lines are on either side of white dashes, while on the other side Caltrans is trying a design where the color of the dashes is split into two sections lengthwise.
Previous experiments with orange striping in Wisconsin, Texas and Kentucky, involved the highway departments using orange paint instead of traditional white or yellow.
“I thought the easiest thing would be to leave that normal striping alone and use orange as a contrast color,” said Brian Hadley, a Caltrans engineer overseeing the project.
States have tried many tactics to improve safety in work zones. According to the National Safety Council, 857 people were killed and 44,240 people were injured in work zone crashes in 2020.
Precautionary measures to warn motorists about construction are commonly used on the road, including barriers, barrels and flashing signs.
But Hadley says motorists are especially attentive to signals on the roadway itself. That’s one reason why highway shields painted on the pavement of interchanges so drivers know which lane leads to the route they want to follow are so popular, he said.
“For myself personally, I feel like when I’m driving, I’m looking more at the road than at the signs,” he said.
Wisconsin used orange paint instead of white paint in certain segments during a massive rebuild of the Zoo Interchange in Milwaukee, making recommendations on the color and type of paint that worked most effectively.
While the new color didn’t cut down on crashes, it proved popular with drivers. Eighty percent of drivers who responded to a survey said the orange color increased their awareness that they were in a work zone, while 83% said the orange was easier to see than white striping.
Kentucky started using orange striping for Interstate 75 in 2019. The state also planned to paint 8-foot-tall letters on the pavement to show a 55-mph speed limit. An evaluation of the project, however, found that speeds remained the same in segments with orange striping and white striping.
A toll authority in North Texas has also experimented with orange striping. Initial results showed 61% of motorists in a survey said the orange raised their awareness that they were in a work zone, while 88% of respondents said they’d like to see the color in other Texas construction zones.
In California, engineers will track the effectiveness of their color scheme using video monitors to evaluate vehicle movements, along with devices to track the brightness and reflectivity of the paint over time.
Hadley hopes the improvements will be significant enough that the Federal Highway Administration and state officials will allow for orange to be used as a contrast color on future construction projects. That would require an interim approval for an exception from the federal Manual on Uniform Traffic Control Devices and from its California equivalent.
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Source: Route Fifty
