Interstate 94 (I-94) generally runs north–south through the northeastern portion of the US state of Illinois, in Lake and Cook counties. It is signed east–west in Illinois in accordance with its general alignment across the country, with west signage aligned with northbound travel and vice versa. I-94 in Illinois is 61.53 miles (99.02 km) long.

Lake County is situated in the northeastern corner of the U.S. state of Illinois, along the shores of Lake Michigan. As of the 2020 census, it has a population of 714,342, making it the third-most populous county in Illinois. Its county seat is Waukegan, the tenth-largest city in Illinois. The county is primarily suburban, with some urban areas and some rural areas. Due to its location, immediately north of Cook County, Lake County is one of the collar counties of the Chicago metropolitan area. Its northern boundary is the Wisconsin state line.