Articulated buses, popularly called bendy-buses, were introduced to London in June 2002[citation needed] when the then Mayor of London, Ken Livingstone, introduced new Mercedes-Benz Citaros to Red Arrow commuter services 507 and 521. While articulated bus operation had been standard in many other countries, the UK had only sparingly tried their use.[citation needed]Therefore, the introduction of the type in London caused a lot of press attention.