THE HISTORIC AMERICAN ENGINEERING RECORD ARROYO SECO PARKWAY HAER No. CA- 265 Location: From Glenarm Street in Pasadena, California, 8.2 miles to intersection with Hollywood Freeway (State Highway 101) at Four-Level Interchange in Los Angeles, California; Los Angeles County, California. Dates of construction: 1938-53 Designers: California State Division of Highways, District VII (Spencer V. Courtelyou, Chief Engineer); City of Los Angeles (Lloyd Aldrich, Chief Engineer); City of Pasadena (Harvey W. Hincks, Chief Engineer); City of South Pasadena (Frank H. Clough, Chief Engineer); Automobile Club of Southern California (Ernest E. East, Chief Engineer); Works Progress Administration, Public Works Administration; United States Bureau of Public Roads Present Owner: California Department of Transportation Present Use: Northernmost portion of California Interstate Freeway 110. Significance: The Arroyo Seco Parkway (Pasadena Freeway) was the first divided-lane, high-speed, limited-access road in the urban western United States and the first stretch of road for what would become the extensive Los Angeles freeway network. The approximately six-mile initial stage of the 8.2-mile roadway, completed in 1940, was envisioned as both a scenic road traversing the Arroyo and a vital traffic conduit linking the expanding cities of Pasadena and Los Angeles.  Engineers and planners attempted to blend landscaping and native plants into the overall design while implementing safety features appropriate for high-speed travel. Construction proceeded alongside the installation of the federally assisted Arroyo Seco Flood Control Channel, necessary to ameliorate seasonal flooding.  As road construction proceeded southward towards downtown Los Angeles in the early 1940s, the road began to more closely resemble a high-speed freeway.  As a prominent example of the evolution from recreational parkways to