Lake Cook Road

At its western terminus at Illinois Route 62 (Algonquin Road), the roadway begins as a two-lane road called Lake Cook Road near a residential neighborhood and commercial area in Algonquin. Further east, the road's name changes to County Line Road at Haegers Bend Road and the road travels through largely rural and sparsely developed sections in Barrington Hills, with a significant amount of dense wooded areas and estate-style development, making for a very scenic drive. However, wildlife is also prevalent in this area, due to the presence of Spring Creek (a popular migratory route for animals in the area), which can make for hazardous nighttime driving conditions. As the road enters the town of Barrington, the road's name changes to Main Street and has an at-grade crossing at the Canadian Pacific Railroad formerly the Elgin, Joliet, and Eastern Railway and traffic notably increases, particularly in downtown Barrington at the intersections of Illinois Route 59 (Hough Street), U.S. Route 14 (Northwest Highway), and the at-grade Union Pacific/Northwest Line, especially during weekday rush periods, when Metra trains stop frequently at the nearby station. As the road continues east through the remainder of Barrington and Deer Park, it runs adjacent to more estate-style development and residential neighborhoods as well as another forested area near Deer Grove Forest Preserve in Palatine.

The road's name changes to Lake Cook Road and as the road intersects with Quentin Road, it becomes a four-lane highway (which it remains for much of the remainder of the route) near the Deer Park Town Center commercial center and soon after intersects U.S. Route 12 near a blighted commercial strip which formally was home to a strip club,[5] which until recent signal and intersection modifications were made, was one of the most dangerous intersections in Illinois. The roadway then crosses Deerpath Lake over a bridge, intersects Hicks Road, and then intersects the terminus of the Illinois Route 53 expressway, near a mass of apartment complexes in Palatine. After this intersection, the road is highlighted by the dense single-family neighborhoods on the south side of the roadway in Arlington Heights and the Buffalo Creek Forest Preserve on the north side of the roadway in Long Grove. As the road intersects Arlington Heights Road near neighborhood commercial plazas, it enters Buffalo Grove and becomes a four-lane boulevard, going past more residential neighborhoods, a small office center, the Buffalo Grove Municipal Complex, and Buffalo Creek, and then intersecting Buffalo Grove Road, Illinois Route 83 (McHenry Road), and Weiland Road, in rapid succession near an historic church and regional commercial plazas. A project in 2016-2018 will widen Lake Cook Road from four-lanes to six-lanes at these congested intersections.[6] After intersecting Weiland Road, the road is then bounded by Buffalo Grove on the north and Wheeling on the south. After Lexington Drive, the roadway widens to six lanes. In this area, it goes past an apartment complex in Wheeling, crosses the Soo Line Railroad (Metra's North Central Service commuter rail line) over a bridge, goes past the Chevy Chase Golf Course in Buffalo Grove, and forms an interchange with Illinois Route 21/U.S. Route 45 (Milwaukee Avenue) near the Westin North Shore Hotel and Convention Center.

The road then crosses the Des Plaines River, and goes through the Potawatomi Woods Forest Preserve before entering Riverwoods, Northbrook, and Deerfield. Here, the road intersects Portwine Road, Sanders Road, and Wilmot Road and forms an interchange with Interstate 94/Interstate 294 (the Tri-State Tollway) at the Edens Spur. This area is surrounded by numerous offices, industrial buildings, and corporate headquarters including those of Baxter International, Walgreens, and Underwriters Laboratories. After Wilmot Road, the roadway continues as six lanes after a widening project complete in 2013.[7] Near Underwriters, the road intersects Pfingsten Road and Metra's Milwaukee District/North Line, where the Lake Cook Road Metra station can be found. Shortly thereafter, the road intersects Illinois Route 43 (Waukegan Road) near a retail area and goes past the Northbrook Court regional shopping mall soon after. The road reverts to a four-lane road after Waukegan Road. The road then intersects Ridge Road, a freight railroad track, Skokie Boulevard, and forms an interchange with Skokie Highway (U.S. Route 41). The road then narrows down to a two-lane road and goes past Chicago Botanic Garden, intersects Green Bay Road, intersects Metra's Union Pacific/North Line at Highland Park's Braeside Metra station near the Ravinia Festival music center, and runs concurrent with, and terminates at, Sheridan Road near the Lake Shore Country Club in Glencoe, only a few hundred feet from Lake Michigan.

Lake Cook Road crosses the paths of the four Metra rail lines servicing Chicago's north and northwestern suburbs.

• Union Pacific/Northwest Line (at-grade intersection at the Barrington station)
• North Central Service (at a bridge, located equidistant between the Buffalo Grove station and the Wheeling station)
• Milwaukee District/North Line (at a bridge at the Lake Cook Road station)
• Union Pacific/North Line (at-grade intersection at the Braeside station)