I was recently using NYSDOT's Traffic Data Viewer (http://gis.dot.ny.gov/tdv) to get traffic counts in Dewitt (as opposed to reading the PDFs), and came across an epic find. Using the Identify tool on a road not only gives a summary of the selected road (it looks like it's displaying the fields from a geodatabase), but it provides a link to the actual report filled out when the data was read from the count station. Here's (http://ftp.dot.ny.gov/tdv/YR2006/R03/31_Cayuga/31_0080.pdf) an example on US 20/NY 5/NY 38 eastbound in Auburn. It gives the exact dates and times the data was taken, the percentage of truck traffic, the exact placement of the count station, and more.
So, has anyone else had interesting finds on a DOT's site?
Considering I sometimes need to get that exact sort of data, that may be very useful. NJDOT is very open with information - they have a count finder through their website that lets you interactively pick out locations and see hourly counts.