Several United States libraries have extensive holdings of road maps.
The American Geographical Society Library, Milwaukee, Wisconsin, has thousands of maps, atlases and guide books of interest to road map collectors and researchers. The collection represents holdings from the American Geographical Society of New York as well as new acquisitions and donations since the collection has been located in Wisconsin (since 1978). To date there are thousands of maps by the likes of: Diversified, Texaco, Shell, Amoco, Sun Oil, Standard, Sunoco, D-X, Diamond, Cities Service, Chevron, Mobil, Gousha, Rand McNally, General Drafting Company, Automobile Clubs, Local gas stations, State Tourism and State Dept. of Transportation maps from all 50 states, as well as Canadian and International road maps and atalses. We also have an extensive set of National Highway Association maps including those produced by the local Highway Associations such as the Lincoln Highway Association, Pikes Peak Ocean to Ocean Highway Association, National Park-to-Park Highway Association and many others. Many items can be found in our online catalog but the majority of our pre 1980 maps are only cataloged in an old fashioned card catalog. General inquiries can be made to firstname.lastname@example.org.
Michigan State University Libraries‘ Map Library has a growing collection of many varieties of maps. Visit their Footpaths to Freeways online history of Michigan road maps.
Osher Map Library, University of Southern Maine, Portland, Maine
Especially noted for their fine exhibitions, the Osher has undergone extensive renovation and improvement.
Harvard Map Collection: Digital Maps, Harvard College Library has over half a million general maps, some of which are available digitally.
Public libraries and library consortia
Kansas City Public Library‘s Missouri Valley Special Collections contain a selection of local maps, including road maps and Sanborn maps.
The Illinois Digital Archives, a service from the Illinois Secretary of State, contains 64 Illinois state official road map scans. Other state libraries constantly contribute images to the archive.
Many public libraries provide access to this electronic union catalog, either on premise, or through online database remote authentication. Keyword/publisher searches bring up many map titles unfamiliar to road map collectors.
The Western Association of Map Libraries provides map date code keys for many different map manufacturers, including the inscrutable Mid-West Map Company.