Completion of the freeway was the second highest priority according to the Highway Development Association in May 1963, after the I-5 freeway. Bidding began on the portion from Broadway in El Cajon to Harritt Road in September 1963. This section of the freeway was to parallel US 80 to the south up to Lakeview Road, and then to the north. This portion of the freeway was scheduled to be complete by May 1965. By January 1965, I-8 had been completed from I-5 east to an interchange with Lake Jennings Park Road, just south of the latter's intersection with the southern terminus of Harritt Road. At a cost of $3.44 million (about $ in dollars), the project reduced the grade and curves at what was known as "Tunnel Hill" that hindered the flow of traffic. The part of the freeway from west of Harritt Road to west of Alpine was up for bidding in October 1964, and the Highway Commission set aside $2.1 million (about $ in dollars) for this stretch in February 1965. A contract for $1.42 million (about $ in dollars) was issued in August 1965. The entire stretch from Lake Jennings Road to Harbison Canyon Road was under construction by September 1965 and was scheduled to be complete by the next year.