Despite widespread recognition that Palo Alto urgently needs to reconfigure its four rail crossings to accommodate increasing train traffic, the city's elected leaders remain paralyzed by indecision when it comes to identifying a set of preferred designs.

The City Council's paralysis was on full display Tuesday night, when members had their first chance since last summer to winnow down six options for reconfiguring the rail intersections at Palo Alto Avenue, Churchill Avenue, Meadow Drive and Charleston Road. The council set a goal a year ago of reaching a decision on "grade separation" — the reconfiguring of rail crossings so tracks no longer intersect with roads — by the end of 2018. Having failed at that, city staff revised the timeline and is now aiming for a decision by spring.

But as the Tuesday discussion made clear, solving the rail puzzle will take many additional months, if not years. After exhaustive debate, council members agreed that the best way to move forward is to keep all the options on the table, including a citywide tunnel that staff had determined was cost prohibitive and an aerial viaduct that has galvanized significant opposition in south Palo Alto.

By a 5-0 vote, with Mayor Eric Filseth and Councilwoman Liz Kniss recusing themselves, the council chose not to eliminate either the viaduct or the tunnel from consideration. It also agreed that redesign of the northernmost crossing, Palo Alto Avenue, should take place as part of a "comprehensive planning effort" for downtown, which even under the best-case scenario will take years to complete.

The council also reaffirmed its earlier decision not to pursue grade separation at the Churchill Avenue crossing, a project that would require three dozen properties to be acquired. The only option on the table for Churchill is the closure of the crossing to traffic in combination with making unspecified traffic improvements elsewhere.

And for the two southernmost crossings, the city will continue to study four options: a train viaduct, a trench south of Oregon Expressway, a rail tunnel and a "hybrid" design that lowers the road and raises the train tracks.

The council also decided on Tuesday to continue to analyze the idea of a citywide tunnel, which remains popular but which staff had recommended eliminating because of its high costs and significant engineering challenges.

According to staff, the citywide tunnel option has the biggest downsides, including property seizures in north Palo Alto to accommodate construction and the high costs of both digging a tunnel and relocating existing Caltrain stations underground. Deputy City Manager Rob De Geus said that as staff had evaluated this option further, it has identified "several significant constraints."

"The cost, for instance, is really significant: not millions but billions of dollars," de Geus said.

But the council was reluctant to remove any designs from consideration. Vice Mayor Adrian Fine said that while there are several options he would like to see eliminated eventually, now is not the time to do so. Fine also said he believes the city needs to do "a little more exploration" of the citywide tunnel before officially eliminating it.

Councilman Tom DuBois agreed and seconded Fine's motion to keep all six options in play, even as he acknowledged that none of them is ideal.

"It does feel like we've been in this process of forcing reductions in options without having options that we like," DuBois said.

Councilwoman Lydia Kou proved similarly reluctant to remove the citywide tunnel. After watching a video simulation of what a tunnel construction would look like, she pushed back against the assumptions made by city consultant Aecom about the proposed tunnel's construction and impacts.

"I'd have hoped to see there would be more creative and innovative ideas, not just one method of doing shoofly (tracks) and tunnel but different scenarios that can come to council for us to look at," Kou said.

Several residents also spoke out in favor of the tunnel, as they have in past city meetings on the rail redesign. Steven Rosenblum told the council that ditching the citywide tunnel would be premature, given that the city has scheduled a March meeting to discuss this option.

"This is a broken process, and I think we're being railroaded. ... I don't think this is the proper way to treat the most popular option at any of the meetings I've attended," Rosenblum said.

Often referred to as the "largest infrastructure project in the city's history," the redesign has been the subject of countless public hearings, numerous community meetings and extensive discussions by a specially appointed citizen committee. It’s being driven by an expected increase in train traffic as a result of Caltrain's pending electrification of its system, which would boost the daily number of trains from the current 92 to 114 in 2022 and to 128 by 2029, not including high-speed-rail train.

"The impact of traffic congestion alone would be very significant if we do not address the rail crossings," de Geus said.

While keeping their options open, council members also recognized that while each design has its benefits, none are ideal. The idea of closing Churchill is facing resistance from Professorville neighborhood residents who believe the move will drive more traffic to Embarcadero and surrounding Professorville streets.

The viaduct option has a few supporters and many opponents, including the roughly 300 residents in south Palo Alto who signed a petition stating opposition to all raised options.

The trench option, while more popular, is also more expensive than the viaduct (its cost is estimated in the $600 million to $800 million range, compared to $400 million to $450 million for the viaduct) and would take longer to construct. The trench would also obstruct Adobe and Barron creeks, requiring the city to build a culvert with a pump/lift station at both the Meadow and Charleston crossings. While these impacts could be lesser under the "hybrid" design, that alternative also comes with numerous complications, including the need to relocate utilities and pump stations, according to an analysis by Aecom.

Several residents from the Old Palo Alto and Southgate neighborhoods on Tuesday urged the council to move ahead with its plan to close Churchill and to pursue traffic improvements on Embarcadero and other nearby roads that would absorb the traffic from the closure. David Shen, an Old Palo Alto resident who serves on the Community Advisory Panel for grade separation, noted that even if the city were to decide today on its grade-separation alternatives, it will take about seven years to get them in place.

"Every day we delay increases our traffic hell beyond the seven years," Shen said.

But Rachel Kellerman, a resident of Professorville, argued that the city should not make any decisions on Churchill until it conducts a traffic study for Palo Alto Avenue and the broader downtown area. Because improvements in one area would necessarily influence traffic circulation in another, the downtown plan that considers Palo Alto Avenue should be put together in conjunction with improvements to Churchill, she argued.

"If the ultimate decision about Palo Alto Avenue and Churchill are segregated into two processes that don't relate, the value of coordinated approach would be lost," Kellerman said.

In making his motion Tuesday, Fine did include the elimination of one idea from future grade-separation discussions: a tunnel for bicyclists and pedestrians near Loma Verde Avenue. (That project could still be explored, however, through a different planning process that the city is now putting together for the north Ventura neighborhood.)

At the end of Tuesday’s discussion, City Manager Ed Shikada acknowledged even if the city continues to make progress on rail redesign, there may not be a set of options that satisfies everyone.

"At the end of the day, I do believe we won't have a scenario in which folks say, 'That's the one we really like,'" Shikada said. "It may be, 'We like it better than the alternative,' which can help us narrow the field."