Skip to main content

California State Route 109

On the south side of San Francisco Bay between US Route 101 and California State Route 84 there are to unsigned short surface routes; CA 109 and CA 114.  Both CA 109 and CA 114 are located with the boundaries of Menlo Park and East Palo Alto, this entry is about the former route CA 109.


CA 109 is a 2 mile state highway running on University Avenue between US 101 in East Palo Alto to CA 84 in Menlo Park.  Northbound traffic departing US 101 from exit 403 must join Donohoe Street and take a brief western jog to reach CA 109 on University Avenue.



CA 109 north travels through East Palo Alto and enters Menlo Park at Notre Dame Avenue.  Notre Dame Avenue north to CA 84 was the first segment of CA 109 that was adopted by Caltrans.  Traffic is slow with speed limits as low as 25 MPH in East Palo Alto.






CA 109 on University Avenue crosses a set of rails before terminating at CA 84.




The north terminus of CA 109 is within view of modern Dumbarton Bridge crossing San Francisco Bay.  The Dumbarton Bridge is a Twin Concrete Girder design which is 1.63 miles in length.  The modern Dumbarton Bridge was opened to traffic in 1984 and was a replacement for the 1927 span which was the first highway crossing of San Francisco Bay.


According to CAhighways the current routing of CA 109 was created in 1984 from CA 84 south on University Avenue to Notre Dame Avenue.  In 1988 legislation was passed which allowed CA 109 to be extended south on University Avenue to US 101 but maintenance wasn't picked up apparently until 1997.

CAhighways on CA 109

The first CA 109 was along Sunset Cliffs Boulevard in San Diego.  The first CA 109 first appears on the State Highway Map in 1964 and was apparently created out of legislation in 1963 according to CAhighways.org.  The original CA 109 was deleted in 1972 and became an extension of I-8. 

1964 State Highway Map 

Interestingly the second CA 109 appears on the 1986 State Highway Map City Insert as CA 209 running south from CA 84 to Notre Dame Avenue.

1986 State Highway Map City Insert

On the 1988 State Highway Map City Insert CA 109 is shown correctly, I'm not sure if the 1986 map was an error.

1988 State Highway Map City Insert

CA 109 appears as a complete route between CA 84 and US 101 on the 1990 State Highway Map City Insert.

1990 State Highway City Insert

Comments

Popular posts from this blog

Interstate 40's Tumultuous Ride Through the Pigeon River Gorge

In the nearly 60 years Interstate 40 has been open to traffic through the Pigeon River Gorge in the mountains of Western North Carolina, it has been troubled by frequent rockslides and damaging flooding, which has seen the over 30-mile stretch through North Carolina and Tennessee closed for months at a time. Most recently, excessive rainfall from Hurricane Helene in September 2024 saw sections of Interstate 40 wash away into a raging Pigeon River. While the physical troubles of Interstate 40 are well known, how I-40 came to be through the area is a tale of its own. Interstate 40 West through Haywood County near mile marker 10. I-40's route through the Pigeon River Gorge dates to local political squabbles in the 1940s and a state highway law written in 1921. A small note appeared in the July 28, 1945, Asheville Times. It read that the North Carolina State Highway Commission had authorized a feasibility study of a "...water-level road down [the] Pigeon River to the Tennessee l...

Massena Center Suspension Bridge

The Massena Center Bridge, also known as the Holton D. Robinson Bridge, has had quite the tumultuous history. Situated on the Grasse River just east of Massena, New York in the hamlet of Massena Center, the Massena Center Bridge is a reminder of the efforts the community has made in order to connect over the river. The first and only other known bridge to be built at Massena Center was built in 1832, but that bridge was never long for this world. During the spring of 1833, the Grasse River dammed itself due to an ice dam, flooded and lifted the bridge off its foundation, destroying the bridge in the process.  The floods were frequent in the river during the spring, often backing up the river from Hogansburg and past Massena Center, but not to nearby Massena. After the first bridge disappeared, local residents had to resort to traveling seven miles west to Massena to cross the next closest bridge, and that was no easy task for a horse and buggy. However, it was many decades befo...

The Dead Man's Curve of Interstate 90 and Innerbelt Freeway in Cleveland

"Dead Man's Curve" refers to the transition ramp Interstate 90 takes between Cleveland Memorial Shoreway onto the Innerbelt Freeway in downtown Cleveland, Ohio.  Said curve includes a sharp transition between the two freeways which is known for a high rate of accidents.  Currently the curve (not officially named) has a 35 MPH advisory speed and numerous safety features intended to mitigate crashes.  When the Interstate System was first conceived during 1956, Interstate 90 was intended to use the entirety Cleveland Memorial Shoreway and connect to the Northwest Freeway through Lakewood.  The Innerbelt Freeway was initially planned as the northernmost segment of Interstate 71.  The extension of Cleveland Memorial Shoreway west of Edgewater Park was never constructed which led to Interstate 90 being routed through the Innerbelt Freeway.   Part 1; the history of Cleveland's Innerbelt Freeway and Deadman's Curve The Federal Aid Highway Act of 1956 was signe...