Freight Train tracks along outdoor ceremony area

How long does the noise last? A minute or two, or super long? I'd ask the venue if there are scheduled times that the train goes through.

A friend of mine got married on a rooftop overlooking a waterway. Gorgeous venue, but the bridge went up for a boat to pass under right as they were saying their vows. This is not a timed thing that they could have planned. It's more-so whenever boats need to pass under. The bridge dings and it causes a lot of traffic backup for about 10-15 minutes. However, it made for cool pictures having the bridge up while they kissed and now it's a funny story. Guests laughed it off.

A train is a little different depending how close it is or how loud it gets. As a guest I'd be a little bothered to be sitting near a loud and rumbling train.

If the train goes by quickly, I wouldn't worry about it. If it does happen during the ceremony, I am sure your officiant could turn it into a funny moment by saying something like "the single train has left the station" or some other train pun. People love a light hearted moment!

I went to college right next to train tracks for freight trains. During graduation, they would just pause for a minute or two to let the trains pass and then continue with the ceremony. I would imagine it would be similar for you. I would also second a PP's recommendation to look at the train schedule and try to schedule your ceremony accordingly.

There is a venue near my house like this. I had my baby shower there and didn't hear much of anything inside. But i did not consider a wedding there for that reason at all. Do you know how frequent the train runs? Anything running every 15 mins or every 30 will interfere you can't plan it too much. Maybe you can view their schedule but if they are behind schedule or ahead of schedule you cannot determine.