Rail replacement bus service
What it really means
When trains cannot run (usually because of engineering works), buses carry passengers along the route instead. It is slower than the train, so allow extra time. Your train ticket is valid on the bus.
Context, tips & common mistakes
When engineering works close a line, buses cover the gap — your train ticket is fully valid on them at no extra cost, railcard discounts and all. The bus stop is usually outside the station, signposted and staffed on busy weekends; follow the 'rail replacement' signs rather than boarding a normal local bus.
Plan around their weaknesses: they are much slower than the train, motion-sickness-prone passengers should sit forward, and luggage space is limited — a problem when the closed line serves an airport. Departure times follow a special timetable shown in journey planners, not the train times on the platform boards. If accessibility matters to you, ask staff about the accessible vehicle options when you arrive.