California State Route 84

State Route 84
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Route information
Defined by Streets and Highways Code § 384
Maintained by Caltrans
Length:	96 mi (154 km)
Restrictions:	Special restrictions No hazardous material in the Sunol Valley between SR 238 and I-680 No tractor-trailers or vehicles over 16.25 tons on the Ryer Island Ferry. Length restrictions may also apply.
Section 1
West end:	SR 1 at San Gregorio
Major junctions:	I-280 at Woodside US 101 in Redwood City I-880 in Fremont SR 238 in Fremont I-680 near Sunol
East end:	I-580 in Livermore
Section 2
South end:	SR 12 in Rio Vista
North end:	I-80 in West Sacramento
Highway system
State highways in California Interstate U.S. State Pre-1964 History Unconstructed Deleted Freeway Scenic ← SR 83 SR 85 →

State Route 84 (SR 84) is a split-section California State Highway consisting of two sections. The first section is an east–west arterial road running from San Gregorio to Menlo Park, across the Dumbarton Bridge through Fremont and Newark and ending at I-580 in Livermore. The route overlaps the freeway segment of U.S. 101 between Woodside Road in Redwood City and Marsh Road in Menlo Park. The segment between Marsh Road and the Dumbarton Bridge has been upgraded to an expressway and is known as the Bayfront Expressway. The segment from the eastern end of the Dumbarton Bridge to the interchange with I-880 has been upgraded to a freeway.

The other section is a north-south arterial road that begins at Route 12 in Rio Vista, passes through Ryer Island (where it connects to Route 220), and ends at the Interstate 80 interchange in West Sacramento. However, plans are underway to turn maintenance of SR 84 through West Sacramento to that city.

A ferry provides the crossing over Cache Slough from Rio Vista to Ryer Island. The ferry, a diesel-powered boat operated by Caltrans, is in operation twenty-four hours per day and charges no toll.

Route 84 is legally defined to continue from I-580 to Route 4 in Antioch, but there are currently no plans in place to bridge the gap at this time. A plan to build a $600 million toll road called the Mid-State Tollway along the proposed route was suspended in 2001 due to local opposition.

Route description

This route is part of the California Freeway and Expressway System and is eligible for the State Scenic Highway System. It is designated as a State Scenic Highway from State Route 238 to Interstate 680 in Alameda County.

Dumbarton Bridge on State Route 84 as seen from Skeggs Point.

The route begins at SR 1 on the Pacific coast near San Gregorio. It then heads northward through San Mateo County crossing the Santa Cruz Mountains. As it enters Woodside, where it intersects SR 35, also known as Skyline Boulevard, and interchanges with Interstate 280 (California). It then enters Redwood City, where it intersects SR 82, which carries El Camino Real through the South Bay. A few miles later, it interchanges with U.S. Route 101, which it overlaps for several miles. Upon exiting, it enters the city of Menlo Park as an expressway, where it intersects SR 114 and SR 109 at intersections controlled by traffic lights. The SR 114 (Willow Road) intersection was the site of the car crash in which author David Halberstam was killed on April 23, 2007.

Route 84 then becomes a freeway at the south end of San Mateo County as it crosses as the Dumbarton Bridge over the San Francisco Bay. Midway over the bridge, it enters Alameda County.

File:La Honda.png

Downtown La Honda on State Route 84.

In Alameda County, it runs northward through the city of Newark, where it begins a concurrency with Interstate 880. Both interchanges with Interstate 880 are partial cloverleaf interchanges, meaning that through traffic on Route 84 encounters traffic lights while joining and leaving I-880. Upon separation, the route loses its freeway status as it enters the city of Fremont, where it has a short concurrency with SR 238. There are plans to construct a new parkway between the I-880 interchange and Mission Boulevard (CA 238), with land being held for the route and an interchange at Fremont Boulevard.

It then leaves Fremont through the historic Sunol Valley. After exiting the valley, it begins an overlap with I-680. After separating, it runs for several miles over a pass, then enters the city of Livermore; it runs along Isabel Ave until it meets I-580, as the end of its southern section.

Upon reappearing, the route begins at SR 12 in Rio Vista. It then follows the Ryer Island Ferry, which carries the route across the Cache Slough. When it leaves the ferry, it intersects SR 220. It continues northward and meets the end of state maintenance at the West Sacramento city limit, about six miles east of an intersection with CR E19. It then enters the city of West Sacramento in Yolo County. It then interchanges with I-80 Business, also signed as U.S. Route 50. As it continues northward, it ends at Interstate 80.

File:California State Route 84 Reed Ave West Sacramento.jpg

The I-80 East bound freeway signage indicating the California State Route 84 (unsigned) Eastern terminus at the Reed Ave interchange in West Sacramento

Major intersections

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, and do not necessarily reflect current mileage. R reflects a realignment in the route since then, M indicates a second realignment, L refers an overlap due to a correction or change, and T indicates postmiles classified as temporary (for a full list of prefixes, see the list of postmile definitions). Segments that remain unconstructed or have been relinquished to local control may be omitted. The numbers reset at county lines; the start and end postmiles in each county are given in the county column.

County	Location	Postmile	Exit	Destinations	Notes
San Mateo SM 0.00-R30.15	San Gregorio	0.00		SR 1 – Half Moon Bay, Santa Cruz
	Woodside	14.95		SR 35 (Skyline Boulevard) – San Francisco, Santa Cruz
		21.54		I-280 (Junipero Serra Freeway) – San Francisco, San Jose	Interchange; I-280 exit 25
	Redwood City	22.68		Alameda de las Pulgas
		24.70		SR 82 (El Camino Real)	Interchange
		25.06		Middlefield Road – Downtown Redwood City
		5.72 5.39		US 101 north (Bayshore Freeway) / Seaport Boulevard – San Francisco	Interchange; west end of US 101 overlap; US 101 exit 408
			West end of freeway on US 101
	Menlo Park		East end of freeway on US 101
		3.59 R25.81		US 101 south (Bayshore Freeway) / Marsh Road – San Jose, Atherton	Interchange; east end of US 101 overlap; US 101 exit 406
		R27.66		SR 114 (Willow Road) to US 101 south – Menlo Park
		R28.19		SR 109 (University Avenue) – East Palo Alto
			West end of freeway
				Ravenswood, S.F. Bay National Wildlife Refuge
San Mateo– Alameda line	Menlo Park– Newark line		Dumbarton Bridge over San Francisco Bay
Alameda ALA R0.00-R28.63	Newark	R3.75	36	Thornton Avenue, Paseo Padre Parkway
		R4.88	37	Newark Boulevard, Ardenwood Boulevard
		R6.01 10.30		I-880 north (Nimitz Freeway) / Decoto Road – Oakland	Interchange; west end of I-880 overlap; I-880 exit 21
	Fremont		East end of freeway on I-880
		8.84 6.92		I-880 south (Nimitz Freeway) / Thornton Avenue – San Jose	Interchange; east end of I-880 overlap; I-880 exit 19
		8.02		Thornton Avenue, Fremont Boulevard
		8.33		Fremont Boulevard, Peralta Boulevard
		9.92		Mowry Avenue – Civic Center
		10.82 3.31		SR 238 south (Mission Boulevard) – San Jose	West end of SR 238 overlap
		3.64 10.83		SR 238 north (Mission Boulevard) / Niles Boulevard – Hayward, Union City	East end of SR 238 overlap
	Sunol	16.93		Sunol (Main Street)	Interchange; eastbound exit and westbound entrance
	​	17.99 R11.04		I-680 south / Calaveras Road – Fremont, San Jose	Interchange; west end of I-680 overlap; I-680 north exit 21A, south exit 21
	​		West end of freeway on I-680
	​	R11.85 17.99		I-680 north – Walnut Creek, Sacramento	East end of I-680 overlap; I-680 north exit 21B, south via a U-turn at exit 21
	​		East end of freeway
	Pleasanton	23.56		Vallecitos Road – Downtown Livermore	Former SR 84 east
	Livermore	R26.22		Stanley Boulevard	Interchange
		M27.75		Airway Boulevard
				I-580 / Isabel Avenue – Oakland, Stockton	Interchange; I-580 exit 51
Gap in route
Solano SOL 0.13-13.67	Rio Vista	0.13		SR 12 / Front Street – Lodi, Fairfield	Interchange
	​	2.49	Ryer Island Ferry across Cache Slough
	​	7.25		SR 220 east – Ryde
	​	12.08		Ryer Road East – Ryde
Yolo YOL 0.00-24.05	​	4.57		Courtland Road – Courtland, Rio Vista
	​	9.53		CR E19 (Clarksburg Road) – Clarksburg
	West Sacramento	15.69	North end of state maintenance at West Sacramento city limit
		19.65		Linden Road
		19.85		Lake Washington Boulevard
		R21.78		I-80 Bus. (Capital City Freeway, US 50) – San Francisco, Sacramento	Interchange; former I-80; I‑80 Bus./US 50 exit 3
		21.84		To Capitol Mall (SR 275, Tower Bridge Gateway)	Interchange; former US 40 / US 99W
		22.06		West Capitol Avenue	Former US 40 / US 99W
		22.68		Sacramento Avenue, Kegle Drive	Sacramento Avenue was former SR 16 east
		23.47		Sunset Avenue – Woodland	Former SR 16 west
		23.67		Harbor Boulevard
		24.05		I-80 to I-5 – Reno, San Francisco	Interchange; former I-880; I-80 exit 83
		24.05		Reed Avenue	Continuation beyond I-80
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus       Incomplete access

External links

• California @ AARoads - State Route 84
• Caltrans: Route 84 highway conditions
• Caltrans: Mid-State Tollway
• California Highways: SR 84
• Live Toll Prices for Dumbarton Bridge