What safety feature is commonly used in roller coasters to prevent accidents?

Lap bars are a commonly used safety feature in roller coasters that secure riders in their seats during the ride, helping to prevent them from standing up or sliding out unexpectedly. They come down across the rider's lap and are designed to fit snugly, providing both security and comfort while allowing some freedom of movement. This design helps ensure that riders remain safely seated through the twists, turns, and drops of the ride.

Shoulder harnesses, while also a safety feature used in some coasters, are not as universally applied across all types of roller coasters. Safety nets are more typically found in the context of certain thrill rides or amusement attractions, rather than as a primary safety measure for roller coasters themselves. Footrests offer additional comfort but do not serve as a primary safety measure for securing the rider in place.