British Transport Police has warned children and young adults not to risk their lives by trespassing on the railways.
Over the coming weeks, officers will be patrolling hotspots in a bid to ward off would-be trespassers who either think the track is a place to hang out or who commit vandalism.
BTP said between 2010 and 2014, 731 people had been caught on the tracks in the rail network between Brighton, Crawley and south of the M25 - 92 between April and June.
More than half of all railway trespassers were aged between 14 and 25.
Chief Inspector Tom Naughton said: “Children and young adults need to understand the dangers of the railway – that’s the message from British Transport Police as our officers spend the next two months targeting trespassers across the network.
“While taking trespassers through the courts remains open to BTP, the main focus of this campaign is prevention – stopping people getting on the track in the first place.
“Our officers have already visited a number of schools to warn children, face-to-face, of the dangers of straying onto the railway.
“We need parents to play their part, too – making children aware of how dangerous a place the railway can be.”