The Lincoln Highway, America's first transcontinental road, originally avoided the Carquinez Strait entirely. Like the Transcontinental Railroad before it, the highway routed travelers south from Sacramento through Stockton, across the San Joaquin River, and over the Altamont Pass to reach Oakland -- a circuitous path dictated by the strait's reputation as unbridgeable. The channel runs deep, scoured by the combined outflow of two major river systems. High winds funnel through the gap between the coastal hills, and tidal currents add unpredictability. Ferry service existed -- the Rodeo-Vallejo Ferry Company began operations in 1913 -- but ferries were slow, weather-dependent, and increasingly inadequate as automobile traffic surged. The original steel cantilever bridge, designed by Robinson & Steinman and costing $8 million, changed everything. Once it opened, the Lincoln Highway was rerouted through Davis and Vallejo, across the bridge, and along the bayshore to Richmond. That new route became U.S. Route 40 and, eventually, Interstate 80.

The story of the Carquinez crossing is really the story of three bridges. The 1927 original was a cantilever design, a marvel of its era. By the 1950s, traffic had outgrown it, and a parallel cantilever span opened in 1958 at a cost of $38 million. For decades, the pair worked in tandem: the 1927 bridge handling westbound traffic, the 1958 span carrying eastbound. Then came the 1989 Loma Prieta earthquake. Engineers determined that the aging 1927 structure was seismically unstable and could not be retrofitted. The decision was made to replace it entirely. The result was the Alfred Zampa Memorial Bridge, a suspension bridge that opened on November 11, 2003. Named for an ironworker who helped build numerous Bay Area bridges -- including the Golden Gate and the original 1927 Carquinez span -- the Zampa bridge cost $240 million. Its dedication was originally scheduled for November 15, but the recall of Governor Gray Davis and Arnold Schwarzenegger's assumption of office forced a date change. Commemorative coins minted for the occasion still bear the original, incorrect date.

Al Zampa spent his career walking steel high above Bay Area waters. He worked on the Golden Gate Bridge, the San Francisco-Oakland Bay Bridge, and the original Carquinez span, among others. The decision to name the 2003 replacement after him was a tribute not just to one man but to the generations of ironworkers who built the bridges that define the region's landscape. The Zampa bridge was assembled by an international coalition: deck sections fabricated in Japan by IHI, tower castings forged from Sheffield steel in England, main cable wire spun by Bridon in England, cable bands manufactured in France, and steel caissons built by XKT Engineering in Vallejo itself. The bridge features a pedestrian and bicycle path, part of a trail network that planners hope will eventually circle the entire San Francisco Bay. It carries southbound traffic from Vallejo to Crockett, while the 1958 cantilever span, seismically retrofitted and repainted, handles northbound lanes.

Tolls have been part of the Carquinez crossing since the beginning. When the 1927 bridge opened, drivers paid 60 cents per car plus 10 cents per passenger. The state purchased the bridge in 1940 and began reducing tolls, eventually eliminating them entirely in 1945. But the 1958 parallel span brought tolls back, starting at 25 cents. Since then, the price has climbed steadily through a series of voter-approved regional measures and state surcharges. Bay Area voters passed Regional Measure 1 in 1988, standardizing tolls at $1 across all seven state-owned bridges. Subsequent measures and surcharges pushed the toll to $5 by 2010, $7 by 2022, and $8 by 2025. All-electronic tolling replaced cash collection in 2020, accelerated by the COVID-19 pandemic. The old toll booths still stand, slowing traffic even though no one staffs them -- a physical reminder of the bridge's layered history.

The 1927 bridge is gone now, dismantled by September 2007, four years after its replacement opened. A 3,000-pound bronze bell that once sat atop one of its piers was removed and placed in storage, awaiting display in a future museum at the Oakland end of the Bay Bridge. The MythBusters tested Nikola Tesla's earthquake machine on the old span before it came down, shaking the bridge at its resonant frequency with a small oscillator -- the vibrations were felt at a distance, though the bridge held firm. National Geographic documented the demolition in an hour-long special. Four books chronicle the crossing's history. From the air, the two remaining bridges -- the 1958 cantilever and the 2003 suspension -- stretch across the strait like parallel sentences written in different engineering languages, one angular and utilitarian, the other curved and graceful, both carrying Interstate 80 over water that people once believed could never be bridged.