There's no such national test.  You'll have to talk to each DOT individually.  Most DOTs don't do a whole lot of field welding of bridges except in repair situation, but TX does a fair amount.

At least I assume you're talking about field welding.  For shop welding, the fabricator you work for will handle your qualification testing.

Hg

AWS'ers,
     All I can add if it is shop welding it is 3 inch clear and the info for New York State is online with
https://www.nysdot.gov/divisions/engineering/structures/manuals/scm
. It is an easy read and sticking iron together is not all book stuff.  I hope this is helpful.
                        Sincerely
                               Len Andersen BSChE CWI
                                    914-237-7689
                                        212-839-6599
                                          212-839-4042 FAX

                       www.lenandersen.com

              POB 1529 / NYC 10116 ( $990 per year Caller

AWS'ers
    Latest contact info I have is
Louisiana Dept. of Transportation and Development
Johnny B. Bradberry, Ph.D., Secretary 1201 Capitol Access Rd.
Baton Rouge, La. 70804-9245 225-379-1201
225-379-1851 (Fax) www.dotd.state.la.us
! Lived there long enough to be an official ---!
                         Len