California State Route 156

State Route 156 west of San Juan Bautista

SR 156 concurrent with US 101 west of San Juan Bautista

The western terminus is at State Route 1 in Castroville. The eastern terminus is at State Route 152 near Hollister. It overlaps U.S. Route 101 for 8 miles (13 km) between Prunedale, and San Juan Bautista. Route 156 passes through Monterey, San Benito, and Santa Clara Counties. Along with US 101, it is the quickest route from the San Francisco Bay Area to the Monterey Peninsula. In addition, SR 156's connection with SR 152 allows direct access to the California Central Valley.

For its westernmost two miles (3 km), Route 156 is a freeway through Castroville, terminating at a Y-interchange with the Route 1 freeway. There is no direct access from Route 156 West to Route 1 North or Route 1 South to Route 156 East. Motorists who want to go from Route 1 South to Route 156 East can do so by using Route 183 South through Castroville. Traffic heading west on Route 156 can access Route 1 North by exiting at the Route 183 interchange and heading north. The route then truncates into a two-lane road between Castroville and Prunedale. Route 156 joins U.S. 101 for the next 8 miles (13 km) before splitting off as an expressway east to San Juan Bautista. Just after the intersection with The Alameda, Route 156 returns to a 2-lane road, then curves north by northeast, with several at-grade signal intersections, including one with State Route 25. Route 156 then crosses into Santa Clara County approximately 1/4 mile (300 meters) before a divided road and terminating at State Route 152 as a partial interchange. However, motorists wishing to use westbound SR 152 must exit at Casa de Fruita as there is no direct interchange between eastbound SR 156 and westbound SR 152.

SR 156 is part of the National Highway System,[3] a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration.[4] The route is eligible for the State Scenic Highway System,[5] and from 1 mile (1.6 km) east of Castroville to US 101 is officially designated as a scenic highway by the California Department of Transportation,[6] meaning that it is a substantial section of highway passing through a "memorable landscape" with no "visual intrusions", where the potential designation has gained popular favor with the community.[7]

The original portion of the route was defined in 1909 and ran from U.S. Route 101 to Hollister. In 1933, the remainder of the route (between Castroville and US 101 and between Hollister and Route 152) was added. It was signed as Route 156 by 1963, but was not part of the original 1934 state signage of routes.

Route 156 was originally routed through Hollister on 4th street and turned left on San Benito Street where it shared a route with Route 25 for 1 mile (as of 2009, SR 25 was rerouted onto a bypass.) before splitting with SR 25, and meeting its current alignment at the current SR 156/ San Benito Road intersection. In 1998, Route 156 was rerouted onto a new bypass of Hollister. A stub of the original route can be seen southeast of this intersection.

Route 156 east originally came to an intersection with US 101. This intersection became dangerous because U.S. 101 traffic didn't stop. This intersection was replaced with an interchange since then. A stub of the intersection can still be seen between the southbound on ramp and the bridge crossing U.S. 101.

Highway 156 experiences heavy truck traffic as it serves as a primary route for moving people and goods between the Monterey Peninsula and the rest of the state. It directly links with Highway 152, one of a small number of passable routes across the Coast Ranges between Monterey Bay and the Central Valley.

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).[9] 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 [9][1][10]	Exit [11]	Destinations	Notes
Monterey MON R0.17-101.32[N 1]	​	R0.17		SR 1 south – Monterey Peninsula	Westbound exit and eastbound entrance; west end of SR 156
	Castroville	R1.11		SR 183 to SR 1 north – Castroville, Salinas
		​	East end of freeway
	Prunedale	​		Prunedale Road	Interchange westbound; at-grade intersection eastbound
		T5.19 95.44[N 1]		US 101 south / Vierra Canyon Road – Los Angeles	Interchange; west end of US 101 overlap
		96.14[N 1]	337	San Miguel Canyon Road (CR G12)	Interchange
		98.37[N 1]	339	Crazy Horse Canyon Road, Echo Valley Road	Interchange
		100.39[N 1]		Dunbarton Road to San Juan Road (CR G11) – Aromas, Watsonville	Closed
San Benito SBT 0.00[N 1]-R18.43	​	0.00[N 1]	342	San Juan Road (CR G11) – Aromas, Watsonville	Interchange
	​	​	West end of freeway on US 101
	​	​	East end of freeway on US 101
	​	3.00[N 1] 0.00		US 101 north – San Jose, San Francisco	Interchange; east end of US 101 overlap
	San Juan Bautista	3.02		CR G1 (The Alameda)	former US 101
	Hollister	​		San Juan Road (SR 156 Bus. east) - Hollister	former SR 156 east
	​	R11.37		SR 25 (Bolsa Road) – Gilroy, Hollister
	​	R13.22		San Felipe Road (SR 156 Bus. west) – Hollister	Former SR 156 west
Santa Clara SCL 0.00-R0.60	​	R0.60		SR 152 east – Los Banos	Interchange; eastbound exit and westbound entrance; east end of SR 156
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Closed/former       Concurrency terminus       Incomplete access

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Wikimedia Commons has media related to California State Route 156.

• Caltrans: Route 156 highway conditions
• California Highways: Route 156
• California @ AARoads.com - State Route 156