Driving on I205 & I580 from Tracy to Dublin, California

Interstate 205 begins at the bottom of I-580's eight-lane descent from Altamont Pass into the San Joaquin Valley. Here I-580 turns southeast to a junction with I-5, paralleling the California Aqueduct and Delta-Mendota Canal along the foothills, while I-205 continues east as a six-lane roadway, immediately crossing both waterways. The first interchange is with Mountain House Parkway, formerly Patterson Pass Road, which serves the planned community of Mountain House. Next is a split with Business 205, a business loop that follows 11th Street through Tracy. As I-205 curves east-northeast and back east through the northern part of Tracy, it has interchanges with Grant Line Road (County Route J4 towards Antioch), Tracy Boulevard (County Route J13 through downtown Tracy), and MacArthur Drive. After several miles without an interchange, the highway ends at a merge with I-5, where traffic can continue northeast to the junction with SR 120 near Manteca and then east on SR 120 towards Yosemite National Park or north on I-5 towards Stockton.[3]

As it connects to I-580, I-205 is a frequently-congested major commuter route to the Bay Area.[4] Signs on eastbound I-580 instruct travelers to take I-205, SR 120, and SR 99 to reach Modesto instead of using the direct, but non-freeway, route SR 132. I-205 also serves to connect the Bay Area with popular weekend destinations such as Yosemite, Reno, and Lake Tahoe. The Altamont Commuter Express provides commuters with an alternate route over Altamont Pass to San Jose and San Francisco, the latter through a transfer to BART.