In urban public transport, provision is made for standing passengers, often called straphangers, to rationalize operation and to provide extra capacity during rush hour. While most travelers may be seated during off-peak services, only a limited proportion will be seated during the peak services. The longer the journey, the less willing passengers are to stand. On intercity rail or coach services, the willingness among passengers to stand is often low or it may be prohibited, with reserved seating to ensure that all passengers can be seated.In aviation, safety measures require all passengers and crew to be seated during take-off and landing, so airlines do not allow passengers to travel without a seat. However, in 2010, Ryanair, a low-cost airline proposed a 'vertical seat' design for use by standing passengers on its aircraft.