Trains around Windsor will run at full capacity as 100,000 people are set to visit the town for the royal wedding.
Great Western (GWR) and South Western Railway (SWR) have said it will be putting on extra trains for the event, with queuing systems in place at certain stations - writes bbc.com
GWR services will rise from two to four carriages, running every 20 minutes,
Four direct, ten-carriage SWR services from London Waterloo to Windsor and Eton Riverside will run ever hour.
The operators are expecting tens of thousands of people to descent on Windsor on 19 May to join the celebration and catch a glimpse of the royal couple.
GWR Managing Director Mark Hopwood said: "This will be one of the largest ever one-day events that has taken place on our network.
"Our aim is to ensure our customers have a great day out and enjoy what will be an international spectacle."
Both operators advised customers to keep luggage to a minimum and wear sensible clothes because of changeable weather conditions.
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