Which feature is unique to stand-up roller coasters?

Stand-up roller coasters are distinct because riders stand throughout the ride, which sets them apart from traditional roller coasters where riders are seated. This standing position alters the dynamics of the ride experience. The design incorporates specific safety features, such as leg supports and restraints, to secure the riders since they are upright during the entire duration of the ride. This unique experience provides a different sensation of speed and motion compared to seated coasters, as riders feel the g-forces differently in a standing position, making it appealing for thrill-seekers who seek something different from conventional roller coasters. Other features, such as over-the-shoulder restraints or vertical drops, are common to various types of coasters and do not define the stand-up category specifically.