A man who lost an arm and a leg after being hit by a train in Sydney's south has warned commuters about the dangers of being distracted near train tracks, amid a rise in incidents.

Jonathan Beninca was run over by a train 16 years ago in Cronulla and has since become a rail safety advocate.

Launching New South Wales' rail safety week on Monday, he said the increasing use of personal technology near train platforms had led some people to act rashly.

"What they need to understand is that a limb can't be replaced, your mobile phone can be replaced, your iPad can be replaced," Mr Beninca said.

"So it's really important that young people are aware that if they drop their mobile phone on the train track, they drop something of importance, go and see the staff."

NSW Transport Minister Andrew Constance said problems had increased with people not being aware of their surroundings while having earphones plugged in or being distracted by personal devices.

"It's happening too frequently, people need to be mindful of what's going on," Mr Constance said.

"We're seeing a lot of things like personal belongings, mobile phones, iPads these types of things going onto the track as people lose hold of them."

"If that happens to you, just go and alert the station staff, don't go and be stupid and think that you can retrieve it and do it in a split second and no-one will notice and everything will be all-right. There's a very clear message in this regard."

Jonathan Beninca was run over by a train 16 years ago in Cronulla and has since become a rail safety advocate. ( ABC News: Danuta Kozaki )

Chief executive of Sydney Trains, Howard Collins, said every year about 4000 people trespass on the tracks for a range of reasons from taking shortcuts to committing graffiti vandalism.

He said there were 24 deaths on the state's rail tracks last year, with over half being self-harm cases.

Mr Collins said all parties, including staff, are affected when a death or serious injured occurs on the track.

"Well having driven a train in the past, I can tell you it's great driving a train but when something's on the track in front of you, you know it's going to take half a kilometre to stop a train," he said.

"There's nothing you can do about it, it's not like driving a car so you're facing the inevitable consequence - and for some of my colleague drivers and people I'm sure here as well - they never drove again."

Mr Beninca said he speaks to a lot of young people during his rail safety education talks and some young people were copying what they see on social media.

"Young people are so de-sensitised," he said.

"They watch clips, ridiculous clips, some of these clips aren't even real, where people have jumped out of the way of a moving train or they've done something...and they think it's real and they think they can do it themselves.

"And that's when they start to take risks and put themselves in situations where they believe it won't happen to them."

Mr Beninca said he removes his prosthetic leg when talking to young people to prove the reality of the dangers of being reckless around train tracks.

"So they can actually see what I look like because when they see there used to be an arm here, there used to be fingers here...it's hard hitting and it really tries to get them to think about their safety and their responsibility."