Southwest

Interstate 15 between the Inland Empire and Las Vegas is one of the highest-volume freight and passenger corridors in the American West, and one of its most deadly. The 150-mile stretch through the Mojave Desert from the Cajon Pass summit to the Nevada state line combines extreme summer heat, monotonous open-road conditions that encourage speeding and drowsy driving, and one of the most notorious truck grades in California — all on a corridor that sees over 50,000 vehicles per day.