The Athens Suburban Railway (Proastiakos) will resume its full services on Monday, May 4, the day when coronavirus restrictive measures are partially lifted in Greece, TrainOSE announced on Thursday. 
To minimize overcrowding, the company devised a real-time-stamped ticketing system that corresponds to specific routes. These tickets are valid for one hour before and up to two hours after the indicated departure time of the selected route. These tickets are checked electronically onboard by train staff. If a passenger is unable to travel or exceeds the time limit, the ticket is canceled or re-stamped to 23:59:59 of the date indicated on the ticket.
These tickets are available at tickets.trainose.gr, via TrainOSE's iOS and Android apps and at physical points of sale. 
Proastiakos runs between Athens and Chalkida; Piraeus and Kiato (Corinth), or the Airport; and Ano Liossia and Koropi.