RELATED LINKS Return to City Guide: Sonoma

An unfortunate by-product of residential development and increased tourism in the Sonoma Valley is that the area's limited network of two-lane rural roadways frequently gets overwhelmed with traffic. On busy weekends, bottlenecks are particularly common south of town where Highway 121, the main route for motorists arriving from the San Francisco area, meets up with Highway 12, the primary artery through the floor of the Sonoma Valley. The stretch of Highway 12 north of the Plaza is also prone to traffic jams. Locals commonly avoid the more congested stretches of highways 12 and 121 by using Arnold Drive, which diverges from Highway 121 a few miles south of town and parallels Highway 12 all the way up to Glen Ellen.

The Infineon Raceway, a large motor sports complex located at the junction of Highways 37 and 121, is another potential source of major tie-ups at the southern approach to Sonoma. Before you hit the road, check the raceway calendar online (www.infineonraceway.com), and if there's a major event planned, try to adjust your schedule to avoid the crush of race fans. It's also possible to by-pass the southern approach altogether by following Highway 101 north to Santa Rosa and exiting the freeway at Highway 12 East, which leads into the northern end of Sonoma Valley.

For travelers who wish to combine a visit to the Sonoma Valley with wine tasting in the adjacent Napa Valley, the stretch of Highway 121 known as the Carneros Highway provides the most direct east-west link. If you want to avoid congestion on the Carneros Highway, however, it's possible to cut directly over the ridge between Napa and Sonoma by turning east off of Highway 12 just north of Glen Ellen onto Trinity Road. This narrow route snakes into the mountains before merging with Dry Creek Road and then the Oakville Grade, which winds down through glorious rural scenery to Highway 29, the Napa Valley's main north-south artery.

A word about traffic safety: Rural highways, confusing intersections and tippling tourists are a dangerous mix throughout the Northern California wine country, where horrible head-on collisions are a grim fact of life. The designated driver in your party should make liberal use of spit buckets in the winery tasting rooms, and keep a sharp eye out on the road for other motorists who have not been so prudent. Special care also is required when sharing the road with the bicyclists and agricultural equipment you're likely to encounter.