There it curves north-northeasterly around Bernal Heights and then northwest around Potrero Hill, meeting the Central Freeway at the border between the Mission District and South of Market.

[13] The roadway was extended to Oregon Avenue in Palo Alto in mid-1932,[14][15] Lawrence Station Road in mid-1933,[16][17] and to Lafayette Street near Santa Clara, across the Guadalupe River from San Jose, by 1934.

[21] Although the highway was designed and built to what were, at the time, high standards, with a 100-foot (30 m) wide right-of-way in most places, it was accident-prone because it lacked a median barrier.

[6][10] One segment of the so-called "Bloody Bayshore" was "Boneyard Hill", a steep grade through the Visitacion Valley near the San Francisco city line, running past a bone meal plant.

Within that city, the new highway continued three miles (5 km) along the present Bay Shore Boulevard to Army (Cesar Chavez) Street and Potrero Avenue.

[19][27] In San Francisco, they rejoined at the present location of the Alemany Maze, with the El Camino route following Alemany Boulevard from near the city line; from there US 101 continued north on Bay Shore Boulevard, Potrero Avenue, and 10th and Fell Streets to Van Ness Avenue, meeting the Bay Bridge approach (US 40/US 50) at Bryant and Harrison Streets.

[19] The state legislature authorized an extension beyond San Jose back to El Camino Real near Ford Road in 1947,[30] which was already under construction, and was completed that year.

Despite this, most crossings were at-grade; only the two ends at Route 115 (Santa Clara Street) and regular US 101 included bridges, the former a diamond interchange and the latter a simple split with additional access to Ford Road.

[38] The original 1947 bridge over Coyote Road remains, though widened in 1990, and is one of the oldest road-road grade separations on the present freeway.

[42] At the time, it was anticipated that traffic along the San Francisco Peninsula would reach the capacity of both El Camino Real and the Bayshore Highway within ten years.

[42] The new roadway, intended for northbound traffic, was constructed east of the existing alignment,[44] separated by a 36-foot (11 m) wide median, permitting a future expansion to four lanes in each direction.

[58] The experiment was deemed a success, and the remaining 0.9 miles (1.4 km) of causeway was put out for bid in 1954,[59] awarded in 1955 to Guy F. Atkinson Co. By that time, over 4,000,000 cubic yards (3,100,000 m3) of fill had already been placed.

[61] A movement to make the four-lane undivided "Bloody Bayshore" safer all the way to San Jose began in Palo Alto.

[23] As a temporary measure, the state lowered the speed limit, installed traffic signals, closed minor crossroads, and prohibited left turns in places.

[62] Contracts for the projects in Santa Clara County had been awarded by 1959,[61] and the Bayshore Freeway was completed to San Jose in 1962, officially opening on February 2 of that year.

[39] 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.