A rail replacement bus service is a temporary or permanent service that uses buses to replace a passenger train service. This can occur for a variety of reasons, such as planned engineering works, unexpected disruptions, or permanent closures of rail lines. The methods of transport used for rail replacement services are different from trains, so there are some things that passengers need to know. Here are some key points about rail replacement bus services:

• Rail replacement buses are usually operated by third-party companies on behalf of a rail operator.
• Passengers should buy a train ticket for their journey as if it was a regular train journey, but catch the replacement bus instead.
• Railway staff will be available to assist customers at stations that are usually staffed, but may not be available at bus stops and meeting points close to, but not at, the station.
• There may be facilities on a train that it is not always possible or practical to have on a replacement service, for example onboard catering.
• Passengers may be able to bring pets, pushchairs, or bicycles on board, depending on the type of vehicle provided.
• Replacement buses may stop only at the railway stations on the route, but they might stop somewhere else if road access is difficult.
• Passengers are not entitled to compensation if they need to catch a rail replacement bus due to planned engineering works or other anticipated disruptions.

Rail replacement bus services are common among urban rail transit systems, mainly because of unexpected service disruptions.