Looking for road meets for 2015 or have an idea for one? See this topic for what's out there already
Your link to the detailed highway history of Oregon doesn't work, though. Here's the correct link:http://egov.oregon.gov/ODOT/HWY/GEOMETRONICS/ROW_Eng/HistoryHighwaysOregon/HSHO.pdf
Here's Iowa: http://www.iowadot.gov/maps//msp/historical/transmaps.htm
The Virginia link seems to have died. Anyone have a new link?
I don't know if there's anything useful here that's not on the other maps, but Oklahoma also has traffic count maps going back to 1937: http://www.okladot.state.ok.us/aadtcnt/Default.aspx?list=staticMaps