If any person driving or leading a vehicle is negligent in crossing an unmanned level crossing, he shall be punishable with imprisonment which may extend to one year.
     Explanation.-- For the purposes of this section, "negligence" in relation to any person driving or leading a vehicle in crossing an unmanned level crossing means the crossing of such level crossing by such person--
         (a) without stopping or caring to stop the vehicle near such level crossing to observe whether any approaching rolling stock is in sight, or
         (b) even while an approaching rolling stock is in sight.