It’s estimated only about 40 percent of services are running but it really depends on where you live.
Members of the Aslef union have walked out and say they haven’t had a pay rise in 4 years.
They’re planning more action on Saturday, with the RMT union striking on Friday.
This means there could be difficulties for people trying to get to the FA Cup final or the Epsom Derby.
Reporter Milena Veselinovic has more: