Illinois County Highway and Traffic Maps Illinois State Library

The two inventories below detail the Illinois State Library’s holdings of two types of the Illinois Department of Transportation’s (IDOT), or its predecessors maps: 1) the general county highway maps and 2) the county traffic maps. Both types of county maps are issued at two scales: 1 inch = 1 mile and 1 inch = 2 miles. Therefore, each Illinois county has four different charts in the inventories:

Inventories of Illinois County Highway and Traffic Maps

Explanations: An x in the column to the right of entries indicates State Library ownership. For example, in the Adams County hgh 1 mi chart, the d1950 x entry means that the ISL owns the 1950 Adams County general highway map at the 1 inch = 1 mile scale.

A number next to an x, such as x1, means that the State Library owns the county map as well as one supplement. One supplement usually indicates that it is a "(city) & vicinity" map. For instance, an x1 in an Adams County chart would mean a "Quincy & vicinity" map. An x3 on a Rock Island County chart would mean an "East Moline & vicinity," a "Moline & vicinity," and a "Rock Island & vicinity" map. A larger number, such as x16 in the Lake County charts, usually means township supplements, one or two townships to a sheet. A number but no x means that the State Library owns only the supplement and not the county-wide map.

IDOT City Street and City Traffic Maps: The State Library holds IDOT’s city street and city traffic maps but they are generally not included in these inventories. A few city street and city traffic maps are, however, included here because these "(city) & vicinity" maps were issued as supplements to the county series.

Availability: These inventories indicate State Library holdings only, not necessarily all that were issued. The State Library can make photocopies upon request for a fee, but does not sell the originals. For more information, or for a print version of these inventories, please call 217-782-7596 or email