GRAND PRAIRIE, TX—In an effort to accommodate passengers who wish to relax and get some rest during their ride, amusement park operator Six Flags confirmed Friday it had begun to add sleeper cars to all its roller coasters throughout North America.According to company sources, the specially modified cars feature private compartments, polished brass lap-bar restraints, and plush seats that can be folded down into a sleeping berth, allowing passengers to slumber peacefully for the full one-to-four-minute duration of their ride.“With our new sleeper cars, Six Flags guests can enjoy all the high-speed thrills of our roller coasters, yet still wake up feeling fully refreshed and energized afterward,” said company CEO James Reid-Anderson, who noted that the compartments feature more than four times the space of regular seats, providing ample room to stretch out for anyone who meets the minimum height requirements.