The signed Route 9, as LRN 114, proceeded North on Saratoga-Sunnyvale Road into Sunnyvale via Mathilda Ave, thence to a jct with Alviso-Milpitas Road (currently signed as Route 237), and a junction with Bypass US-101 (LRN 68). On October 18, 1956, the Highway Commission adopted the routing for a future freeway location for Route 9 from Bayshore Freeway north of Moffett Field, generally following Stevens Creek to an existing Route 9 location north of Azule near Saratoga. The route signed as Route 9 then proceeded on the current Route 237 alignment into Milpitas. It ran east as Route 237 to Route 17 (LRN 69; now I-880).
Before the current bridge over the Guadalupe River was constructed, it took a route into Alviso via Gold Street north and 1st Street southwest back to current Route 237.
Total estimated project cost is ,427,000 for capital and support.
"Route" usually indicates a state shield signed route, but said route may be signed as US or I.
In 1934, Route 9 was signed along the route from Santa Cruz to Milpitas via Redwood Park.
In Saratoga, the original signage of Route 9 diverged from the present signage.
It appears in 1839 in the land grant San Vicente y Santa Monica, on which the modern city was founded in the early 1870s. The route was originally to have been named the ""; that name was changed during planning in 1958.
That probably came from the original Route 26 routing along Olympic Blvd, which itself was renamed from 10th Street in honor of the 1932 Olympics.