Southern California's extensive freeway network usually means that the shortest distance between Point A and Point B has the word "interstate" in the directions. Heading southwest on Interstate 15, come down through California's High Desert cities of Barstow and Victorville before crossing into the Inland Empire at the Cajon Pass. Picking up Interstate 215 at the base of the pass takes you through San Bernardino and the eastern edge of Riverside before you're able to grab Interstate 15 again at Temecula and take it directly through the northern suburbs into San Diego. This route clocks in at about four hours and 40 minutes with good traffic flow. If you're heading south over the pass in the morning, expect a wave of commuters driving from the desert into the basin.
There's no need to get off Interstate 15 after coming over the Cajon Pass. Interstate 15 bends westward before continuing south through the heart of L.A.'s Inland Empire suburbs. If you need to pull off to stretch your legs, top off the tank or grab a snack, this is a safe area with lots of services along the freeway. Shoppers will also be tempted to lengthen the drive with stops at the Ontario Mills outlet mall or the outlet center at Lake Elsinore. Foodies will want to pull off at Tom's Farms south of Corona for fresh produce, nuts, candy, wine and the intoxicating smell of freshly baked loaves of French bread. At about four hours and 45 minutes, you're adding just a few more minutes without stops. But since you're veering closer to L.A., you can expect heavier commuter traffic depending on your travel time.
If you want to take the oceanside route from the L.A. area, you're going to have to add a few minutes to your ride in the L.A. area. Take Interstate 15 to either State Route 60 (Pomona Freeway) or State Route 91 (Riverside Freeway) to State Route 57 (Orange Freeway) south. Take into account the time of day, though, as the 60 and the 91 are both commuter outlets into Los Angeles that can be heavily congested. The 57 meets Interstate 5 in the heart of Orange County, and heads south through Mission Viejo and San Juan Capistrano before beginning to hug the coastline at San Clemente. With 17 miles stretching along Camp Pendleton, you'll get unspoiled coastline and hills before hitting Oceanside and following the interstate into San Diego. At just over five hours, you could see further delays from Orange County traffic.
Can you avoid all big-city congestion on the way from Las Vegas to San Diego? Yes, but it will add time to your drive. On the other hand, if passing through the L.A. area during rush hour would be unavoidable, you could save a chunk of time and a boatload of stress with the backroads route. Feel the open air of the west as you head south out of the Vegas area on U.S. Route 95 and cross the California border toward Needles. Take the 95 until Blythe, where you'll keep heading southwest on State Route 78. Pick up Interstate 8 west at El Centro for a straight shot through the Cleveland National Forest and into San Diego. This is a rural route with few stops and hot summer weather that clocks in at just under seven hours, so make sure to take advantage of gas stops and bottled water.
