Interstate 305

Interstate 305 (California)

Interstate 305
Route information
Maintained by Caltrans
Length	5.3 mi (8.5 km)
Existed	November 14, 1980–present
NHS	Entire route
Major junctions
Major intersections	I-5 in Sacramento US 50 / SR 99 / I-80 BL / SR 51 in Sacramento SR 275 / SR 84 in West Sacramento I-80 in West Sacramento
Location
Country	United States
State	California
Counties	Sacramento County, Yolo County
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future State highways in California Interstate US State Scenic History Pre‑1964 Unconstructed Deleted Freeways

Interstate 305 (I-305) in California is a short, unsigned interstate highway designation applied concurrently to a portion of U.S. Route 50 (US 50) and Interstate 80 Business (I-80 Bus) within the city limits of West Sacramento and Sacramento. Despite being an official Interstate Highway, I-305 lacks any signage identifying it as such.

History

The designation of I-305 in California dates back to the development of the Interstate Highway System in the mid-20th century. The exact year it was assigned is unclear, but it likely coincided with the planning stages for I-80 through California.

Since the 1990s, the Federal Highway Administration (FHWA) has relinquished control of certain Interstate segments to individual states. In California, this has resulted in "piecemeal relinquishments" where the federal designation remains, but the state assumes maintenance responsibility. I-305 is one such example.

Route Description

I-305's entire two-mile length overlaps with US 50 and I-80 Bus. It begins at the western edge of the Sacramento city limits, where US 50 transitions from a freeway to a more conventional arterial road. The route continues eastward through West Sacramento, following the shared US 50/I-80 Bus alignment until it reaches the interchange with Interstate 5 (I-5). Here, I-80 Bus departs the concurrency, and I-305 terminates.

Significance

While I-305 itself is a short and largely inconsequential highway segment, its existence highlights a few interesting aspects of the Interstate Highway System:

• Concurrency: The shared designation with US 50 and I-80 Bus demonstrates how Interstate Highways can coexist with other federal and state routes.
• Unsigned Routes: I-305's lack of signage is uncommon but not unheard of in the Interstate system. It signifies a route that serves an internal administrative function for the FHWA rather than providing a distinct travel designation for motorists.
• Federal-State Cooperation: The case of I-305 showcases the ongoing adjustments within the Interstate system, where federal and state transportation agencies manage the network collaboratively.