A train drivers' union is stepping up demands for a new track surveillance system for the railways, saying it would dramatically improve safety.
The safety system could prevent accidents at level crossings
The track-to-train device, of a type already in use in Hong Kong, would save lives by warning drivers of obstacles on the line, Aslef said.
The union claims Network Rail told it the system would be too expensive.
But Network Rail denies this, saying it is "extremely interested" in any system which can detect objects on its tracks.
The union wants the system, called Trackmaster and developed by a firm in south Wales, to be installed at level crossings initially.
It could then be installed along the tracks, helping to avoid collisions between trains and obstacles placed on tracks by vandals.
Aslef officials say the system would have prevented last year's crash at Ufton Nervet in Berkshire, in which seven people died when a train hit a car on a level crossing.
The union is debating rail safety at its annual conference in Scarborough on Tuesday, where it will argue the case for installing the system is "irrefutable".
National officer Andy Reed said: "Network Rail has told us the system is too expensive and was not a priority.
"This is a prehistoric attitude to take and they are so wrong.
"They give us glib messages about wanting the public to travel in safety, yet they are not prepared to invest money in this type of technology which would ensure there is more protection."
A Network Rail spokesman said nine out of ten incidents at level crossings involved members of the public flouting rail safety rules, sometimes even zigzagging between the barriers in bid to get through before the train arrives.
He said a panel of experts had been set up in the wake of the Ufton Nervet crash to consider 145 ideas for systems similar to the Trackmaster device.
He added: "The industry is developing a research project into these ideas and products with the most merit.
"At this point it would be premature to opt for one supplier until all potential systems have been investigated and fully assessed."