The RMT union members at Southern Rail have once again gone on strike.
It's the latest walkout in the long running dispute about driver only operated trains. Southern says on most routes a normal service will operate - although some cancellations are possible.
The strike centres on driver-only operation and follows the failure of the latest peace talks.
The union say it is unsafe which is denied by the company in a row lasting seventeen months, the longest industrial disputes in British history.