Yes, AWS D1.5 is the bridge welding code. The plate test coupon will be similar to a AWS D1.1 plate test coupon, the only difference will be that the welder/test taker cannot use any power tools for cleaning, only hand tools.
You didn't say, so I am going to assume that you are talking about a welder performance qualification/certification.
edit: whoops, I was too slow replying, that ole Al was too quick on the keyboard
Generally speaking, the last person you want to take advice from is a friend who 99% chance has as little understanding of the process as yourself.
People are always telling others to get this cert or that cert and even tell them how it works and they don't have a clue. Only word of mouth or a past experience that was actually wrong, etc.
First question that comes to mind for me is, why do you want a cert of any kind? ...Have you worked on bridges? Is there a job opportunity in the immediate vicinity and/or future?
Second, how much experience to you have and in what sector? Structural, pipe, sheetmetal, etc?
What process do you intend to test with? Do you know what will be used on the job you MAY be interested in?
If you are looking to go to work for a company, they will normally have to qualify/certify you themselves even if you have a cert from somewhere else. If you have previously qualified elsewhere then you really don't need to go GET a Bridge Cert, go get a job and they will test you and your previous certs should be all the help you need to get your foot in the door.
Past that, Al and John covered the essential differences in the testing between Bridge and Structural. Then again, you didn't say you knew anything about structural or what you may be comparing the D1.5 test to. So, if you are comparing it to sheetmetal or aerospace, or brazing, or plastic welding.....forget everything they said because it doesn't matter because there will be many other more applicable differences.
He Is In Control, Have a Great Day, Brent