Nearly a decade after Palo Alto embarked on a journey to redesign its four rail crossings, the city is preparing to answer a critical and divisive question: Should the city close Churchill Avenue to traffic near the train tracks?

The City Council will weigh on Monday a recommendation from its advisory panel to close the crossing to cars altogether — a proposal that would also involve a new bike underpass across the tracks and a host of road modifications at key intersections north and south of Churchill. The option is one of three still on the table for Churchill, along with a train viaduct and an option known as the "partial underpass," which would depress Churchill west of the rail corridor and allow drivers to cross the tracks and turn left or right on Alma Street.

Palo Alto is one of several cities along the Peninsula that are moving ahead with grade separation, a redesign of rail crossings so that streets and tracks no longer intersect. Mountain View is working with Caltrain to redesign the intersection at Castro Street, which would be closed to traffic at the tracks, and at Rengstorff Avenue, which would be lowered under the tracks. San Mateo just completed a grade-separation project at 25th Avenue that features a "hybrid" design of raised tracks and lowered roadway. Burlingame is planning to take a similar approach at its Broadway rail crossing.

Redwood City is narrowing down grade-separation alternatives for Whipple Avenue and the city's other rail crossings, while Sunnyvale is evaluating underpass options for its two crossings, at Mary and Sunnyvale avenues.

The main driver of these projects is Caltrain, which is moving ahead with electrifying its tracks and expanding its train fleet. The long-awaited improvement to the rail system will, however, entail more gate-down time and longer car queues at some of the existing rail crossings.

The traffic impacts on Churchill are expected to be particularly severe. A study commissioned by the city in 2019 indicated that once Caltrain electrification is complete, gates at the crossing will be down about 15% of the time and it would take between 10 and 12 minutes for cars heading north on Alma during the morning commute to complete a left turn onto Churchill. The queue of cars lining up to make that turn would stretch for five blocks, past Seale Avenue.

Meanwhile, the queue of cars heading east on Churchill toward Alma would stretch all the way to El Camino Real.

But while the Palo Alto council agrees that this is unacceptable, members have struggled over the years to reach a consensus on an alternative. In both 2018 and 2019, the council had set a goal of selecting its preferred design for the three crossings by the end of that year, only to see the deadlines pass with no resolution.

During its last discussion, which took place on Aug. 23, members considered possible options for the East Meadow Drive and Charleston Road rail crossings and agreed to eliminate the viaduct from further consideration, leaving them with three options: a trench, an underpass and a "hybrid" design.

While the council broadly supports moving ahead with grade separation, members have acknowledged that all design alternatives are flawed and each is sure to encounter opposition. Old Palo Alto residents who live near the tracks have vociferously objected to having a viaduct just outside their yards, while their counterparts in Professorville have warned that closing Churchill would steer cars to other key east-west routes, most notably Embarcadero Road.

The closure has also stirred opposition in Southgate, a neighborhood just south of Churchill and just west of the tracks, where many residents have criticized the option because it would cut off their primary route across the tracks.

For Churchill resident Mohamed Hadidi, who supports closure, the choice is easy. The underpass alternative, Hadidi told the council during an April discussion, remains unrefined and unacceptable in its current form. The viaduct, meanwhile, is undesirable because of its visual impact.

"The stark choice here is between two alternatives: number one, inflicting a concrete monstrosity on the neighborhood, which will indelibly change is character for the worse, and number two, a potential minor increase in traffic at some intersections and a slight inconvenience for some Southgate residents," Hadidi said.

Southgate resident Steve Carlson strongly disagreed and suggested at the April hearing that Churchill's closure would worsen traffic conditions in various areas of the city. Barbara Hazlett, who lives in Professorville, called the grade separation effort "one of the most transformative and potentially destructive matters of this town and the Peninsula" and suggested that the city's proposed traffic improvements would not sufficiently mitigate the impacts of the closure.

"One neighborhood's gain should not come from another's loss," Hazlett said.

One factor that everyone agrees on is that the impacts of the decision will spill out well beyond the Churchill rail crossing. To address the fact that drivers will necessarily seek other routes once Churchill is closed, the Expanded Community Advisory Panel (XCAP), a specially appointed citizen commission that was charged with helping the city pick its grade-separation alternative, recommended a suite of mitigations, including reconfiguring Alma Street near Embarcadero and adding a host of turn lanes at El Camino's intersections with Embarcadero and with Oregon Expressway.

Capping 18 months of deliberations, the commission voted 6-3 to select Churchill's closure, coupled with a list of road improvements, as its preferred alternative. The majority noted that the closure is "by far the lowest cost option," with a price tag of between $50 million and $65 million, according to XCAP's final report, which was released in March. (The partial underpass has an estimated cost of $160 million to $200 million, while the viaduct would be between $300 million and $400 million.)

Supporters of the closure alternative also lauded its minor visual impact when compared to a viaduct or an underpass, as well its benefit for bicyclists and pedestrians.

"By fully separating bicycle and pedestrian traffic from both vehicular traffic and the train, a safer and more enhanced crossing condition can be created for cyclists and foot traffic in and near Churchill Avenue," the report states. "Proposed mitigations at Embarcadero and Alma also address shortcomings in the current bicycle and pedestrian paths there."

While the three XCAP members who voted against closure — Chair Nadia Naik, Keith Reckdahl and Phil Burton — requested more information about the underpass, the majority concluded the partial underpass is "already an expensive alternative that is unlikely to be improved with additional design iteration."

On Monday, it will be the council's turn to weigh in. It will consider two questions: Should the city eliminate any of the remaining alternatives for Churchill Avenue? And if not, what other information does it need to finally make a decision?

A new report from the Office of Transportation suggests that gathering additional information for all three rail crossings won't be easy or cheap. One of the questions that XCAP had flagged was the need to explore the potential that Caltrain and high-speed rail would create a four-track segment in Palo Alto, an option that is included in the "high growth" scenario of Caltrain's business plan. But evaluating how a four-track alignment would mesh with the existing alternatives would require the city to spend between $90,000 and $110,000, according to the city's report.

Updating a transportation study to consider traffic volumes in the year 2040, as some residents have urged, would cost another $55,000. (The current analysis only considers traffic conditions up to 2030.) A geotechnical study that would explore the impacts of grade separation on groundwater would cost between $130,000 and $160,000, while evaluation of "box jacking" — a construction technique that could significantly expedite construction — could run as high as $600,000, according to the staff report.

These studies, as well as others pertaining to shadows, urban design and refinements to the underpass alternative, are anticipated to cost between $1.25 million and $1.73 million, according to staff. Unless the council proposes a different direction, most of these studies would be conducted by the city's consultant, Aecom.

Not everyone believes that these studies are necessary. Larry Klein, a former Palo Alto mayor who served as vice chair of the Expanded Community Advisory Panel, urged the council at the Aug. 23 discussion not to spend city funds on analyzing Caltrain's and the California High Speed Rail Authority's prospective plans for a four-track segment.

"This isn't Palo Alto's problem," Klein said. "This is a combination of Caltrain's problem and more specifically High-Speed Rail's. … We shouldn't be spending any money on it."

He also suggested that it's too soon to spend money on an urban design study, which according to city staff would cost about $125,000 and involve evaluation of such things as public art, landscaping and pedestrian amenities.

Transportation staff also note in the new report that many of the studies that council members and residents have requested are typically conducted later in the development process. They also pointed out that these studies "must be considered preliminary, since responsible agencies such as Caltrain will provide limited guidance and feedback at the current conceptual design stage."

"Nonetheless, to the extent these studies provide community stakeholders greater confidence in decision-making, the costs involved represent a small percentage of the ultimate costs of grade separation construction," the report states.