San Diego County needed roads in order to compete with adjoining counties and to bring commerce and people between towns and cities. A coastal highway or road was imperative and after the turn of the century, it was a necessity. With the invention and rising popularity of the automobile, it could no longer wait. For years Northern San Diego seemed at times completely cut off from San Diego and even to Los Angeles. Smaller communities were at times inaccessible, especially during the rainy season. An established inland route from Rancho Encinitas to Mission San Luis Rey bypassed the coastal towns. In 1909 the County Board of Supervisors established the Highway Commission. Members of the commission included A.G. Spaulding, E.W. Scripps, and John D. Spreckels.

Much credit is given to this early commission due to its foresight and vision. In fact, San Diego was touted as the "birthplace of California's highway system" in a speech given January 5, 1938 by Frank Forward, Chairman of the San Diego Chamber Highway Committee.

California copies its modern highway system from the San Diego County Highway Commission of about 1909 when our road program was being mapped out and administered by the late E.W. Scripps, John D. Spreckels and A.G. Spaulding. Our plan was so successful that the State took Austin B. Fletcher and C.C. Carleton to initiate the State Highway Program.

The coast route from Oceanside to San Diego was one of great importance for residents of San Diego County. A coast route was more efficient than the inland route, and would connect communities and take full advantage of Southern California's greatest natural resource, an ocean view. This new road would follow closely the railroad line through most coastal cities and eliminate inland treks while connecting communities and bringing travel into vital areas, mainly through downtown and business districts. Residents, businessmen and tourists alike anxiously awaited the completion of the new route. In 1925 the coast road officially became part of the U.S. Highway 101. Over a span of nearly 30 years, it would transition through a number of realignments, route changes and widenings until finally the ever-increasing traffic proved too much and the need for a new super highway would have to be addressed.