SR 91, also known as the Riverside Freeway, is a major highway in Southern California. It runs approximately 50 miles, connecting the cities of Los Angeles and Riverside. The freeway serves as a vital route for commuters and travelers, facilitating access to various neighborhoods and commercial areas. The highway features multiple lanes in each direction and includes several interchanges with other major routes, such as I-15 and I-605. SR 91 is known for its heavy traffic, especially during peak hours, making it an important focus for regional transportation planning and infrastructure improvements.