The Consumer Product Safety Commission voted Wednesday to write mandatory rules to regulate the four-wheel vehicles, after more than 100 deaths since 2003. Riders have suffered dozens of injuries, too - some leading to amputations.

ROVs, also called side-by-sides, are two-passenger motorized vehicles designed for drivers 16 years and older. They resemble a cross between a rugged-looking golf cart and a miniature-Jeep, and have a roll cage - metal bars framing the cab.