Compton Drive is shut both ways between Summerdown Road and Pashley Road due to resurfacing work during the day time on Compton Drive.
On the rail network there is a fault with the signalling system at Littlehampton Southern Rail said.. The signals have failed and the track circuits which detect train movements aren’t working.
No trains can run from or to Littlehampton and all lines are blocked, a spokesman added
Tickets are being accepted on Stagecoach buses route 700 between Littlehampton, Bognor Regis and Chichester.
He said: “No trains can run to or from the station until engineers have fixed the fault.
“If you’ve not yet set off for the station then please delay travelling until later if you can.
“If you have to travel now then your journey will take longer than usual and you will need to use your ticket on Stagecoach 700 bus.”
Thameslink said trains that usually run between Horsham and Peterborough, will now run between Horsham and London Bridge and then between Finsbury Park and Peterborough.
Brighton to Cambridge services will now run between London Bridge and Brighton.
This is due to damage to the overhead electrical wires, which means no trains can run to or from London Kings Cross, a spokesman added.