Quick off-topic question: Do Departments of Transportation normally charge for records requests like these? Like, for instance, to find maps of old alignments of routes. I see others mention that they go to DOTs to do the research, and I'm curious if the DOT charges for access to that information or not.
It varies from DOT to DOT. Typically the access a member of the general public gets is either a matter of courtesy or is granted under the state open-records statute. Most open-records laws allow, but do not require, cost recovery, and this gives DOTs considerable latitude in developing their own policies with regard to charging for access to records. In my experience "Don't push your luck and you probably won't have to pay" holds true for a good many DOTs, but there are a few which are positively nasty--"We will need to look up these records, and you're going to have to pay us $X per hour," then, "If you want to look at these records, you're going to have to pay $Y an hour for a member of staff to supervise you," etc.
This said, a few general observations can be made:
* If you want to inspect documents in person and they are relatively easy to retrieve, normally a charge won't be made. It is courteous to ask for permission before taking digital camera copies of originals (unless posted policies say explicitly that it is allowed); I would be very surprised if it were ever refused.
* If you want copies, you can expect to pay for paper copies at whatever the DOT considers to be its standard reprographic rates (this is true for, e.g., copies of old county maps made from Mylar originals, which I got at NMDOT a number of years ago).
* If the document you want has been scanned or otherwise exists electronically, you may have to pay for a CD or DVD copy if the DOT has to supply the optical media. You may be able to avoid this if you supply the media yourself, or if it is possible to transfer the data online (e.g. through FTP upload, an in-house file-hosting service, or even email if the document is small enough).
In terms of supports, at a DOT you can expect to find records on ordinary paper, drafting linen, various types of blueprint/whiteprint paper, Mylar, and microfilm (reels, sheets, aperture cards, etc.). Some (almost certainly not all) of these will have been scanned at one time or another, producing images in varying formats, with TIFF and JPEG (in that order) being the most popular, and PDF widely and increasingly used as a container format. XPS is also starting to appear but has not yet broken through. For records "born digital" (created in a CAD or office productivity program), source files and PDF plots or prints may also be available.
The basic procedure is to identify the type of record you are interested in and then talk with the custodian for those records to determine what is feasible in terms of copying, scanning, inspection in person, etc. If the records you are interested in are especially old, like route maps of state highways designated in the 1920's, you will also need to look at the DOT's and the state government's records retention policy. Most states require that records over a certain age which are no longer in current use be turned over to a state archives agency, where they are kept and made available to researchers in a publicly accessible reading room. DOTs tend to guard their construction plans jealously since in principle a 1910's bridge plan can be pulled out for a rehab job in 2011, but most of the planning and policy documentation tends to be shipped off to archives.
Some state DOTs are starting to make certain records available online through document management systems with Web interfaces. MnDOT does this with survey maps and construction plans, and GDOT does it with construction plans. This is not something that has broken through yet, however, partly because the systems that have so far been tried have not scaled very well. Other state DOTs have "here today, gone tomorrow" models of document provision--for example, Alabama DOT puts highway construction plans online up until the date of letting, after which they vanish and then you pay $3/sheet if you want extracts of anything. Personally I try to do what I can online, generally by mining the document management systems I have access to and also making damn sure I have my own private archive of the fly-by-night material.
