The Illinois DOT undertook the construction of a 4-mile stretch of Interstate 290/state Route 53 in the northwest suburbs of Chicago. This stretch of road was removed and replaced between March and October 2003. The estimated project cost was $62.3 million—the largest Chicago-area project of the year. To provide a greater measure of alkali-silica reactivity (ASR) protection with a more economical concrete mixture, slag cement (formerly called ground granulated blast furnace slag) was used to replace, pound-for-pound, a portion of the Portland cement.