I work for the NYSDOT Region 6 out of Hornell, NY. At one time, my duties included handling the NYSDOT welding certification exams. At that time, we would actually go to a location of an individual's preference. The individual would be responsible for providing location, equipment and plates on a date of mutual choosing. I would monitor the test, make out the paperwork, and send the plates to Albany for X-rays. I would then distribute the pass (cards)/fail (letter) info after getting the results back from Albany. NYSDOT is made up of 11 regions. Region 6 out of Hornell covers the area of Allegany, Chemung, Schuyler, Steuben and Yates counties. Region 5 is out of Buffalo and Region 4 is Rochester, etc. This service was once free of charge. However, that has changed in most regions. Region 6 passed the duties over to Alfred State College in Alfred, NY. ASC holds its NYSDOT certification tests on a scheduled basis. They provide everything you need except personal equipment and welding rods. There is a fee. Most regions have similar arrangements...some test out of union halls, BOCES, etc.
If you would like specific info on the NYSDOT field welding certification, the website below will explain the procedure.
https://www.nysdot.gov/portal/page/portal/divisions/engineering/structures/repository/files/FW_Brochure_4-07_0.pdf