deployed as successfully as the conventional large steering wheel. Passenger automobile regulations implemented by the U.S. Department of Transportation required the locking of steering wheel rotation (or transmission locked in "park") to hinder motor vehicle theft; in most vehicles, this is accomplished when the ignition key is removed from the ignition lock. See steering lock. Other designs The driver's seat, and therefore the steering wheel, is centrally located on certain high-performance sports cars, such as the McLaren F1, and in the majority of single-seat racing cars. As drivers may have their hands on the steering wheel for hours at a time these are designed with ergonomics in mind. However, the most important concern is that the driver can effectively convey torque to the steering system; this is especially important in vehicles without power steering or in the rare event of a loss of steering assist. A typical design for circular steering wheels is a steel or magnesium rim with a plastic or rubberized grip molded over and around it. Some drivers purchase vinyl or textile steering wheel covers to enhance grip or comfort, or simply as decoration. Another device used to make steering easier is the brodie knob. A similar device in aircraft is the yoke. Water vessels not steered from a stern-mounted tiller are directed with the ship's wheel, which may have inspired the concept of the steering wheel. The steering wheel is better than other user interfaces and has persisted because driving requires precise feedback that only comes from a large interface. Early Formula One cars used steering wheels taken directly from road cars. They were normally made from wood (necessitating the use of driving gloves), and in the absence of packaging constraints, they tended to be made as large a diameter as possible, to reduce the effort needed to turn. As cars grew progressively lower and cockpits narrower throughout the 1960s and 1970s, steering wheels became smaller, so as to fit into the more compact space available. Spokes in steering wheel The number of spokes in the steering wheel has continuously changed. Most early cars had four-spoke steering wheels. A Banjo steering wheel was an option in early automobiles. They predate power steering. The wire spokes were a buffer or absorber between the driver's hands and the drum of the road. Most were 3- or 4-spokes made of four or five wires in each spoke, hence the