What Are The Half-Black And Half-White Stripes On The Highway For?

Most motorists understand the importance of paying attention to lane lines and road stripes while driving. However, it's not always clear what these stripes mean. Like orange lines on the freeway and the new road strips confusing drivers along Texas highways barriers, road stripes that look half-black and half-white might cause some confusion. Luckily, this pattern isn't directing motorists to do anything specific. Under federal guidelines, black isn't considered a marking color when it's paired with white. It's only there to enhance contrast. That means you don't have to worry about breaking some unknown traffic law if you spot these on the road. Known as contrast marking, this design is meant to make lane lines easier to see in certain conditions.

There are various situations in which lane lines and other road stripes can be hard to see. For example, white stripes can be difficult to spot when the pavement underneath is already light in color, such as concrete or faded asphalt. Certain lighting conditions can also make the lane lines less visible, causing them to blend into the road surface. Pairing white stripes with black sections is one way to address this, as the added contrast boosts their visibility.

Contrast markings won't help much in every situation, though. If snow, sleet, or ice covers the road, the black section gets buried along with the white ones. In that case, it helps to know where you should drive when snow hides the road lines.

It's also worth noting that this pattern isn't limited to white lane lines. Federal guidelines allow black to be paired with other road marking colors, such as, yellow, red, or blue, wherever light pavement doesn't provide enough contrast. The purpose is the same every time: using contrast to improve visibility.

Remember, this isn't the only unfamiliar marking you might encounter while driving. You might also wonder what those yellow flaps on the road are actually for. When you don't know what a road stripe or marking means, don't assume it doesn't matter. Check you state's driver's handbook or Department of Transportation website to fill in any knowledge gaps. Doing so is key to staying safe.