What is the purpose of rumble strips installed on the edge of roads?

Rumble strips are safety features installed on the edges of roads primarily to alert drivers who may inadvertently drift off the road. When a vehicle runs over rumble strips, it produces a distinct sound and vibrations that serve as a wake-up call to the driver, helping to regain their attention and steer back on course. This is especially important in preventing accidents caused by distractions, fatigue, or loss of focus.

The other options relate to different functions. For instance, indicating road construction typically involves signage rather than rumble strips, and speed limits are communicated through posted signs. Lane guidance, while important, is usually facilitated by lane markings and not rumble strips. Thus, the primary role of rumble strips is to provide a tactile and auditory warning to drivers, enhancing road safety.