Illinois Route 15 is a state highway located in southern Illinois, stretching approximately 90 miles. It runs east-west, connecting the cities of East St. Louis and Dixon. The route serves as a vital link for local traffic and provides access to various communities along its path. The highway passes through several towns, including Belleville and Mount Vernon, and intersects with major routes like Interstate 57 and U.S. Route 45. Illinois Route 15 is essential for regional commerce and travel, facilitating the movement of goods and people across the area.