Q: Could you clarify some new road markings for me? There’s a stretch of road I drive that has a trail crossing, and leading up to it there is a series of white bars partially across the road lane, just before a pedestrian crossing sign. Is this a crosswalk? Are vehicles required to stop for pedestrians attempting to walk across a state highway?
A: There are a variety of ways to try to get drivers to slow down. Speed limit signs, speed humps, police writing speeding tickets, those digital signs that show how fast you’re going; we’re familiar with these approaches. But what about mind tricks? I’m putting this method in a category I’ll call “traffic safety through psychological manipulation.”
Those bars you encountered are most commonly called Optical Speed Bars or Speed Reduction Markings. For anyone unfamiliar with them, visualize this: As you drive in your lane, you see a pair of thick white bars projecting from both the fog line and the center line about 18 inches into your lane. And maybe there’s a third bar in the center of the lane, leaving gaps where your tires go. Ten feet later there’s another set of bars. Looking ahead, you see about 20 sets of these bars, each one closer to the one before it, until at the end there’s a gap of about five feet between the last sets of bars. (The actual number and spacing of bars depend on approach and final speeds.)
The Manual on Uniform Traffic Control Devices describes the progressively reduced spacing of the bars as designed to “give drivers the impression that their speed is increasing.” It’s a psychological trick to make you feel like you’re going too fast. They’re used in conjunction with other warnings, like a curve ahead sign or, in your situation, a pedestrian crossing sign.
You described the markings as unusual, and there’s a reason for that. The official guidance on speed reduction markings says they “should be reserved for unexpected curves or other usages.” They’re not supposed to be used every time there’s a need to reduce speed. They’re meant for locations where the need to slow down might come as a bit of a surprise. Most commonly they’re used on curves, but an unexpected pedestrian crossing would fit too.
Optical Speed Bars are not, as I’m sure you’ve already figured out, crosswalks. They don’t grant right-of-way to anyone, but they do give you a warning of a potential hazard ahead. And if there is a pedestrian already in the road, please stop for them, regardless of who was supposed to yield.
Speed bars are not the only subtle way to reduce driver speeds. Narrowing the width of traffic lanes, where appropriate, changes driver behavior. Even if the amount of pavement doesn’t change, just moving the fog line over a foot can slow down traffic and reduce crashes. Like the speed bars, narrower lanes make drivers feel like they’re going too fast.
And then there are things that seemingly have nothing to do with traffic safety that, if planned intentionally, actually do. For example, community gateways (the big signs with landscaping around them welcoming drivers to a city) can help to slow down drivers when placed in speed transition zones. So can landscaping. When trees or shrubs are planted close to the edge of a road it narrows the optical width of the roadway, similar to repainting the fog line to make a lane narrower. These methods can trick us into driving at safer speeds, even when we don’t know they’re doing it.
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