Back in the "old days" the crews would go from place to place on a scooter. Some were machine powered, many were hand powered. Nowadays, track gangs and rail crews use "hi - railers" regular vehicles that have been modified with hydraulic rail wheels.
This photo was taken from a safe location on public property located on US 90 near Scott, Louisiana. Do not tresspass on railroad property to take photographs. If you are llucky, you will only be arrested for tresspass. You may be killed, today's locomotives are very quiet, and you may be pre-occupied with "getting the shot" and not hear the train's horn. Don't become a statistic.