A judge at Birmingham Crown Court also fined signalman Adrian Maund £1,750 for his part in the death of Jane Harding, whose car was struck by a train in Herefordshire in 2010.
Network Rail, which was found guilty of breaching the Health and Safety at Work Act by failing to install an automatic barrier locking system, was also ordered to pay £33,000 in prosecution costs.
Mrs Harding, 52, died when the car she was a passenger in was hit by a train in the village of Moreton-on-Lugg in January 2010.
Her husband Mark, who was driving the car, suffered serious injuries in the collision, which happened seconds after Maund raised the crossing's barriers in the mistaken belief that the train had already passed.
A two-week trial heard that Network Rail had opted not to fit a safety system at the crossing which would have prevented the barriers being lifted when a train was approaching.
Maund, 43, of Caswell Crescent, Leominster, Herefordshire, was convicted in February of failing to take reasonable care for the safety of people using the crossing.
Weighing up the culpability of the defendants with the consequence of their actions, the judge said: "Obviously the harm caused is extremely high - a life has been needlessly lost.
"This tragedy could have been avoided if Network Rail had installed an approach locking system (at the crossing) which would have rendered it impossible for a signalman to raise the barrier."