I set a contraband unit in Baltimore and a Brigade combat unit in Philly to repair a rail line and then move to an adjacent region. Both rail lines were repaired. However, neither unit was able to accomplish this and move to an adjacent region in the same turn. No bad weather was present.
On a second run through, both repaired their rail line and moved to the adjacent region. It actually appeared that the Brigade was faster at repairing the rails.
I'm the 51st shade of gray. Eat, pray, Charge!