Arroyo Seco Parkway

America's first freeway (1940), Los Angeles to Pasadena, National Scenic Byway, New Deal era design.

The Arroyo Seco Parkway (now Interstate 110) is America's first freeway, opened in 1940, connecting downtown Los Angeles with Pasadena. Designed as a landscaped divided highway with no traffic lights, no intersections, and graceful entry ramps, it was a showcase project of the New Deal era. Listed as a National Scenic Byway, it remains notable for integrating high-speed road design with the Arroyo Seco valley landscape.