State Route 58 takes the southernmost route through the Sierra Nevada and allows motorists to travel between Northern California and points to the east, such as Las Vegas and Interstate 40, without having to face the extreme traffic congestion of greater Los Angeles. State Route 58 and Interstate 80 are the only freeways to cross the Sierra Nevada. The route also offers an alternative to the often treacherous Donner Pass to truckers traveling from the San Francisco Bay Area to points eastward; prior to the construction of Interstate 80, the road (as U.S. Route 466) was heavily used for this purpose.