Crash Rates on Expressways and Tollways in the Chicago Region

Crash rates were calculated for expressway/tollway segments in the Chicago region based on Illinois Department of Transportation (IDOT) crash data from the years 2008-2012. The values represent crashes per 100 million vehicle miles of travel and serious or fatal crashes per 100 million vehicle miles of travel. Total crashes for each category are included. The segments are one-tenth of a mile in length and are directional. The segments are generalized and combine all local, express, and reversible lanes into a single road segment. Ramps are excluded. The AADT is based on 2010 IDOT data which was corrected when appropriate. The VMT was calculated by multiplying the AADT by the segment length.