The agency laid out that best-case scenario Monday night at the National Nordic Museum, where about 375 people gathered to discuss the project’s future. Ballard’s planned Smith Cove, Interbay and Market Street stations were declared unaffordable by the Sound Transit board in May. The board set aside $300 million to continue design work while leaders seek a way to pay for them.

To keep the stations on track, Sound Transit says it needs about $1 billion by 2030 for land purchases, followed by $7 billion to $9 billion by 2033 to begin construction from Seattle Center to Ballard. The agency is also studying slimmer station designs and other changes intended to lower costs. Its current schedule calls for construction of the Seattle Center-to-Sodo tunnel to begin in 2032, with the Ballard extension starting the following year.

“We’ve identified the path to delivering the entire Market Street extension by 2042,” Sound Transit CEO Dow Constantine said.

That date is already seven years later than the 2035 service promised when voters approved higher transit taxes. If the financing plan falls through, the agency acknowledged, the three stations could be postponed until 2060.

The uncertainty around Ballard is part of a broader regional budget squeeze. Sound Transit disclosed a $35 billion long-term shortfall last year as it works toward expansions serving West Seattle, Everett, Tacoma, Issaquah and South Kirkland, as well as Ballard. The agency has delayed schedules, cut some planned parking and commuter-rail improvements, and is considering borrowing for longer than 40 years to spread out payments.

Sound Transit’s existing tax revenue — from property, sales and vehicle taxes — totals about $2.4 billion a year, or roughly $700 per person, according to figures presented at the meeting. The 58-mile system carries about 165,000 riders daily. Ballard Link is projected to become one of the network’s busiest additions: early estimates anticipated 70,000 daily rides between Ballard and Westlake, and 135,000 between Ballard and Sodo, including riders making shorter trips.

The agency’s financial assumptions include a 35% federal contribution for future projects in Seattle. Sound Transit leaders said federal grants are not currently being held up by political disputes because the West Seattle and Ballard projects are not fully designed. But the funding plan depends on billions in federal support, and Constantine said the outcome will depend in part on national elections and the next Congress.

Meanwhile, agency designers are considering less costly stations at Seattle Center and Sodo, among other changes. Sound Transit says it remains on stronger financial footing for the approximately $18 billion tunnel from Sodo through downtown to Seattle Center, with a target opening in 2042. That project would not, by itself, provide the planned stations in Smith Cove, Interbay or Ballard.

Community leaders at the meeting pressed for improvements while residents wait. Seattle City Councilmember Dan Strauss, a Sound Transit board member representing Ballard, said, “Failure is not an option.” Attendees also called for restored express buses between Ballard and downtown. Mayor Katie Wilson voiced support for bus lanes, while her proposed city sales-tax increase, Proposition 1, would primarily fund additional bus service.

Pierce County Executive Ryan Mello, who is next in line to chair Sound Transit’s board, said the agency is committed to getting light rail to Market Street. Ballard Alliance Executive Director Mike Stewart voiced frustration with repeated delays, noting that the expected timeline has moved from 2036 to 2039 and now 2042.

For a fast-growing neighborhood designated as a regional urban center, the difference between the best-case plan and a 2060 opening would mean decades more reliance on buses and road travel. Whether Sound Transit can close the gap will depend on cost reductions, local and federal funding, and decisions still years away.