Grapevine Canyon, or Canada De Las Uvas, was named for the wild grapes that grow on its slopes by Spaniards in the 1700′s. The town of Grapevine has been a major stop along this highway ever since the Ridge Route was built in 1915. This first paved alignment was one of the most torturous sections of US 99 in Southern California. It had more than a few very sharp curves, some of which ended up with names such as “The Loop” and “Deadman’s Curve”. Both of those curves still exist today, though partially removed and cutoff from the new roadways. Grapevine Grade received its first pavement in 1919, a “full” 20 foot slab with curbing and little in the way of a shoulder. The original location of the “town” of Grapevine was at the bottom of the grade. It consisted of a motel, store, gas station, and restaurant.
In 1933, a new alignment of US 99 was built. It ran along the current southbound lanes of I-5 for most of the grade. Deadman’s Curve and the Loop were eliminated at that time. When the concrete was first poured, only two lanes were built. About a year later, the third lane was added making the center lane the passing lane. Since the original location of Grapevine was bypassed, it was partially relocated onto the new grade, this time in the canyon. While it was rather conveniently located, it did suffer from one fatal flaw. It was near the bottom of a very long and steep grade. As a result, runaway trucks smashed through on a few occasions.
In 1943, the grade was widened to four lanes with a metal and wood barrier. In October 1946, a concrete barrier was installed along the grade replacing a wood and steel barrier. The reason was that trucks were using the old barrier to slow down, which would destroy the barrier. The new “parabolic concrete divider” was designed so that trucks could not use it to slow down. Drainage in the canyon was also improved to help alleviate erosion problems.
All of the original alignment was redone in 1959-1960 when the grade was reconstructed as eight-lane I-5. This eliminated a lot of the old Ridge Route alignment as well as some of the 1934 alignment of US 99. The northbound lanes were constructed first, then traffic was shifted onto them as the southbound lanes were reconstructed. In 1960, the new freeway was fully opened to traffic.