Vasco Road
| Maintained by | Contra Costa County, Alameda County |
|---|---|
| Length | 17.7 mi (28.5 km) |
| North end |
 SR 4 in Brentwood
|
| South end | Tesla Road in Livermore |
Vasco Road is a roadway over the Diablo Range that connects Livermore and Brentwood, California. Although it is not part of the California State Highway system, it is the principal north–south commuter route serving eastern Contra Costa and Alameda counties. The two counties are each responsible for maintaining the portion of the road within their boundaries.
The traffic count in 2008 was estimated at more than 25,000 vehicles per day. Weekend traffic is also heavy in spring and summer, when residents from other parts of California flock to the recreation areas along the Sacramento - San Joaquin River Delta.
Originally, Vasco Road was a two-lane, very narrow road that began at U.S. Highway 50 (now Interstate 580) and wound over the Diablo Range and through the Kellogg Creek valley. In 1957, Alameda County linked three other streets inside Livermore to extend Vasco to Tesla Road. A ribbon-cutting ceremony opened the new Vasco Road on August 1, 1958.
Booming population growth caused a sharp increase in housing prices throughout the Bay Area. People working in Silicon Valley and the Tri-Valley areas began moving into the relatively undeveloped East County area of Contra Costa County. By the early 1990s, traffic congestion on Vasco Road had become severe and accidents were frequent.
In 1996, concurrently with the construction of Los Vaqueros Reservoir, a 12.8-mile (20.6 km) segment of Vasco was relocated and widened to accommodate increased traffic and heavy trucks. The old roadway was submerged by the reservoir. When the road re-opened, it carried about 16,000 vehicles per day. In 2009, Vasco Road was extended northwestward from Walnut Street to Marsh Creek Road, where it joined the third segment of John Marsh Heritage Highway (California State Route 4 Bypass, now part of California State Route 4). In 2010, a section of the road in Alameda County was relocated and widened, eliminating a steep narrow section with several switchbacks.
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Wikipedia