Which statement is true about properly functioning anti-lock brake systems?

The statement about properly functioning anti-lock brake systems (ABS) that is accurate is that the brakes may lock up at speeds less than 10 miles per hour.

In an ABS, the primary function is to prevent wheel lock-up during hard braking situations, thus allowing the driver to maintain steering control. However, the system is designed to become less effective at very low speeds, typically below 10 miles per hour. At these low speeds, the hydraulic modulator may not react rapidly enough to prevent locking up because of the limited time and space available for the system to engage and disengage the brakes. This characteristic can lead to wheel lock-up when braking force is applied unexpectedly or aggressively at low speeds.

Understanding this behavior is essential for drivers, particularly in scenarios like winter driving where sudden stops might occur at lower speeds. This awareness helps drivers to adjust their braking technique accordingly when they know they might be operating under those conditions.