The Southern railway strikes are back on after the government vetoed a deal.
If you want Southern train service towards Gatwick or anywhere else south of London for the next couple of days it is worth checking.
Southeastern and Southwest trains on similar or parallel routes are likely to be busy.
Southern conservatively expects 2 out of 5 trains to be cancelled or significantly changed.
Tube lines which parallel Southern lines in inner suburban areas will be much busier.
This is part of the push the government is making to remove the safety critical Guard from the trains.