Palo Alto's meandering path to choosing new designs for its rail crossings appeared to have hit a milestone in 2021, when the City Council unanimously agreed to drop from consideration the idea of building a train viaduct to cross Churchill Avenue.

Residents near Churchill had broadly opposed the idea of having elevated trains zip along just feet from their yards and over their homes, and the debate ultimately came down to a choice between closing the street entirely or creating an underpass for cars with ramps that would allow turns onto Alma Street.

A city survey showed the viaduct to be the least popular option among respondents. And a specially appointed citizens committee known as the Expanded Community Advisory Panel did not recommend the viaduct, which would cost between $300 million and $400 million to construct and would raise the tracks about 20 feet.

"The viaduct is the most expensive. It's the ugliest, and it requires some concessions from Caltrain and stuff like that," former council member Eric Filseth said at a November 2021 meeting, just before the council unanimously voted to remove the viaduct from consideration.

But while this option remains off the table, for viaduct supporters things are starting to look up. Next week, the council's Rail Committee will consider placing the train viaduct back on the table, a reversal that would both be highly unusual and politically tricky.

The City Council on June 12, however, revised its evaluation criteria for the redesign of Palo Alto's rail crossings in a way that opened the door to the viaduct option. Instead of committing the city to "minimizing" visual impacts of grade separations (the configuration of roads and train tracks so they don't intersect), the criteria now calls for merely "considering" visual impacts when making a decision.

The subtle revision could raise the viaduct's profile, given that in its low ranking among the options was caused in part by its poor score for "minimize visual changes along the corridor."

It also helps that some of the council members elected last fall are less averse to considering the elevated structure than those whom they replaced. Council member Julie Lythcott-Haims said she was open to the viaduct option during her campaign last year, while council member Vicki Veenker, who serves on the Rail Committee, sounded noncommittal during the April 26 discussion of the evaluation criteria.

"Even if we don't have the viaduct currently on the table, who knows how the winds blow?" Veenker said.

Chief Transportation Official Philip Kamhi wrote in a new report that the city has heard concerns from members of the Palo Alto Bicycle and Pedestrian Advisory Committee and from the Palo Alto Unified School District about pedestrian crossings of the railroad tracks and requested another review of the viaduct option. Kamhi also noted that it's appropriate to revisit alternatives given the recent changes to the evaluation criteria.

"The additional measures in the evaluation criteria include reviewing impacts such as connectedness, corridor travel times, pedestrian and bicycle circulation during and after construction, traffic inducement, sustainability, sea-level rise, utility relocation, long-term maintenance costs, and visual and privacy considerations along the corridor," Kamhi wrote.

Local resident Adrian Brandt is among those who support the viaduct. During the Rail Committee's discussion of the new evaluation criteria in April, Brandt urged the council to consider objective criteria for bicycle and pedestrian connectivity – measures such as the number of turning movements that are interrupted or preserved.

"Under those criteria, I think the viaduct would do a lot better," Brandt told the Rail Committee.

Even so, the viaduct may have a hard time overcoming council and community opposition. Mayor Lydia Kou voted against the revised evaluation criteria, saying she opposes changing "minimize" to "consider" when it comes to the visual impacts of grade separation options.

"With potentially the viaduct being discussed and brought back as an alternative, I think the stronger language is needed to minimize visual and privacy impacts," Kou said.

The choices currently on the table

So far, the Churchill rail crossing is the only one for which the council has selected a preferred alternative: a partial underpass that would submerge Churchill under the tracks west of Alma, allow cars to turn on Alma and include new underpasses for bicycles and pedestrians. That could change if the Rail Committee votes next week to bring the viaduct back for consideration and if the full council endorses that recommendation.

The city is also considering three options for the Meadow Drive and Charleston Road crossings, which are being examined in tandem: a trench, a "hybrid" that combines raised tracks with lowered roads, and an underpass for cars. The Rail Committee will debate on June 20 whether to shrink the list to two by scrapping the trench idea.

According to engineering estimates, the trench option would cost between $800 million and $950 million -- well more than the other two options. The hybrid has an estimated price tag between $190 million and $230 million, while the underpass is projected to cost between $340 million and $420 million.

It's not just the costs that make the trench a tough sell. Kamhi noted that Caltrain is currently exploring the potential for four-track segments along the corridor to allow trains to pass one another. According to Kamhi, Caltrain has indicated a strong need for the four-tracking segment north of Mountain View Caltrain station, which will likely impact the crossings in south Palo Alto.

"The Rail Committee has leaned toward pausing further analysis of the trench alternative, mainly due to its high cost and its feasibility challenges in accommodating and addressing the four tracking needs of Caltrain," Kamhi wrote.