It's the second day of industrial action on the UK's railways this week, with members of the Rail, Maritime and Transport (RMT) union staging a walkout affecting Southern, Northern and Merseyrail train services.
The first day of action was Tuesday this week, in line with the RMT's announcement of strikes last month.
Today, Southern rail said it will run a normal service on most routes but there will be some alterations.
A reduced service will run on the following routes:
- Clapham Junction - Watford Junction (A limited service will operate between these stations at peak times only.)
- Ashford International - Hastings
- Brighton - Hove/West Worthing
- Littlehampton - Brighton/Portsmouth & Southsea
Southern services to and from Guildford will not run, passengers are advised to use South Western Railway services to complete their journeys.
Northern said it will run around 46 per cent of its usual services, with the majority of available trains running between 7am and 7pm. It warned customers: "These trains, and any replacement buses that run, are usually very busy. Therefore please carefully consider whether your journey is necessary."
Meanwhile, reduced service will run across the Merseyrail network. Most services will run between 7am and 7pm with a gap in service during the day. Liverpool Lime Street will also be closed because of major improvement work at the station. Merseyrail services will not call at Liverpool Lime Street.