between Los Angeles and the San Joaquin Valley via the Mojave Desert and Tehachapi Pass. In 1910, Beale's Cut was bypassed by the Newhall Tunnel. Constructed by Los Angeles County, it was too narrow for two trucks to pass each other inside. As a result, in 1939, the tunnel was completely removed (or "daylighted") when the road was widened to four lanes. Additionally, by 1930, a bypass road was constructed to avoid Newhall Pass via Weldon and Gavin canyons, which is the current route of I-5. Both routes were eventually built as freeways. The Gavin Canyon route became I-5, and the main north–south route via the Ridge Route. The Newhall Pass route became SR 14, which is the main route between Los Angeles and the growing high desert communities of the Antelope Valley. It is also still a part of the important Midway Route, which is the primary alternate route when I-5 is closed (via SR 58 and SR 14). The interchange has partially collapsed twice due to earthquakes: the 1971 Sylmar earthquake and the 1994 Northridge earthquake. As a result of the 1994 collapse, this interchange was renamed the "Clarence Wayne Dean Memorial Interchange", honoring a Los Angeles Police Department motorcycle officer killed when he was unable to stop in time and drove off the collapsed flyover ramp from SR 14 south to I-5 south. After both earthquakes, the collapsed portions were rebuilt and surviving portions reinforced. In the evening of October 12, 2007, two trucks collided in the southbound tunnel that takes the truck bypass roadway under the main lanes near the Newhall Pass interchange. Fifteen trucks caught fire, killing three people and injuring ten. Ridge Route The Ridge Route refers to the section of highway between Castaic and Grapevine, through the Tejon Pass. The highway had its origins in the early 1910s, when a route was needed to connect Los Angeles to the Central Valley. Some believed that the only option was the route through the Mojave Desert and the Tehachapi Mountains, but a new route was discovered through the Tejon Pass. This route became known as the Ridge Route and saw almost constant planning, construction, and improvement from 1914 to 1970. The first road was completed in 1915. It was a slow, winding, two-lane road through the mountains with a speed limit of in some places. However, the need for improvements was realized soon after it