Network Rail fears a tragedy could happen if people continue running across level crossings as the barriers come down.
There have been several incidents of pedestrians who have still been on the tracks, as the barriers are lowered around them.
They have now released CCTV pictures highlighting the number of people trying to cross when it's not safe.
Rail bosses say the problem is particularly bad at two crossings in Lincoln City Centre.
In one instance, a man was caught on camera lifting the barriers, to run across the tracks.
Network Rail is now considering plans to build a two bridges over the crossings at High Street and Brayford Wharf.