Only 12% of attacks on the railways are detected, according to figures from the British Transport Police.
Transport Police admit that detection rates are low.
The force says there were more than 2,500 incidents of so-called route crime in the 12 months to March.
Crimes included missiles being thrown at trains as well as attempts to derail rolling stock.
The police say the detection rate of such crimes is low but add that the level of route crime has dropped 16% compared with the previous 12 months.
Last week a train driver narrowly missed being blinded in one eye after stones shattered the windscreen of his cab.
The force says attacks on the rail network typically increase during the school holidays as most of them are carried out by children.
Drivers have also reported everything from car bonnets to shopping trolleys and double beds being thrown or dragged on to rail lines to see what happens if a train hits them.
The British Transport Police (BTP) say the detection rate is low because of the unique problems of trying to police the railways.
'Startling increase in crime'
Meanwhile, the Conservatives said that figures from the BTP showed that there had been a dramatic increase in the number of offensive weapons found on trains in England and Wales.
The number of crimes recorded for the possession of offensive weapons increased from 618 in 2005/6 to 818 for the period between 1 April 2006 and 21 January 2007. The final figure for this year is not yet available.
Chris Grayling, the shadow transport secretary, said: "This is another sad reflection on the state of our public transport.
"The reality is that people are becoming increasingly scared of using buses and trains late at night and these figures show why.
"How can the government hope to encourage people out of their cars and on to public transport when there are such startling increases in crime?"