MG44 Help

[Mr Grumpy]

You will need to read the manual through a couple of times to avoid this kind of frustration, if you look in the movement section it states....
"Travel Mode represents units in a column formation, and for towed artillery, being limbered. Roads have no effect on units that are not in Travel Mode. While in Travel Mode, units are less combat effective and are more vulnerable to enemy units. Towed artillery units must be in Travel or Rail Mode in order to move. A unit in Travel Mode has a white bar at the bottom of its counter in 2D graphics mode and has the letter T following its Movement value in the Hex Info Area ."

...and most important for your question....
"A unit must be in Travel or Rail Mode in order to use a bridge. "

So a careful read through will answer 90% of situations you will come across. :)