According to Dekema, planning for I-805 began in 1956. The original routing for I-805 was approved as an Interstate Highway in July 1958. It was added to the state highway system and the Freeway and Expressway System in 1959 as Route 241. I-805 was expected to reduce traffic on what was then US 101 between Los Angeles and San Diego, when the former was opened. Route 241 was renumbered to Route 805 in the 1964 state highway renumbering, and I-5 was designated along the route from Los Angeles to San Diego. Further planning was underway in 1965, with the goal to have the route built by 1972, the federal highway funding deadline. This was to be the first freeway in the area with no prior road along its route that it would replace; the goal was to provide a bypass around San Diego for those traveling to Mexico, and improve access for local residents. By June, houses along the route in the North Park area were being sold, as the land was needed for the first stretch of the freeway to be constructed. The next year, Dekema confirmed that the first portion of what was known as the Inland Freeway to be built would be between Home and Adams avenues.