Kerb

A kerb (also spelled "curb") is a raised or painted edge that runs along the corners of a racetrack, marking where the official racing surface ends and helping drivers navigate turns more effectively.

Kerbs are usually painted in bright, alternating colors—most commonly red and white stripes—so drivers can easily see them while traveling at high speeds. Think of them like the painted lines on a regular road, except they're often raised a few inches above the track surface and have a bumpy texture that drivers can feel through their steering wheel.

The main job of a kerb is to show drivers exactly where the track limits are. In racing, cutting corners by driving off the track can give an unfair advantage, so kerbs create a clear boundary. If a driver goes beyond the kerb with all four wheels, race officials may penalize them for exceeding track limits.

However, kerbs aren't just boundaries—they're also tools that skilled drivers use to go faster. This technique is called "riding the kerbs" or "kerbing." By allowing one or two wheels to run over the inside kerb at the apex (the tightest point) of a corner, drivers can take a straighter, faster line through the turn. This can save fractions of a second per lap, which adds up significantly over an entire race.

Not all kerbs are created equal. Standard kerbs are gently raised and designed to be driven over safely at speed. Flat kerbs sit flush with the track and essentially extend the racing surface. Sausage kerbs are much larger, rounded obstacles placed in specific locations to discourage drivers from cutting corners—these can actually launch a car into the air if hit incorrectly, making them controversial in the racing community.

Different types of kerbs require different approaches. Some can be attacked aggressively without consequence, while others—like tall, sharp "scraping kerbs"—can unsettle the car or even cause damage to the suspension and underfloor components if hit too hard. Experienced drivers learn each track's kerbs and adjust their driving style accordingly.

Weather and track conditions also affect how drivers use kerbs. In wet conditions, the painted surface of a kerb can become extremely slippery, making them dangerous to ride over. The bumps can also upset the car's balance more easily when grip is already limited.

Watching how professional drivers use kerbs is fascinating. Onboard camera footage often shows the car bouncing and shaking as wheels ride over kerbs, with drivers making constant tiny steering corrections to keep control. It's a delicate balance between extracting maximum performance and maintaining car stability, and mastering this skill separates good drivers from great ones.