Two months ago, Sound Transit unveiled its most ambitious light rail package ever: $50 billion, 58 new miles of rail, long-awaited new lines in the city to Ballard and West Seattle. But as the agency took its plan out to the public for feedback, one factor was undermining even the most enthusiastic light rail supporters' excitement about the package, known as Sound Transit 3: It was going to take too damn long. Light rail wouldn't reach Ballard until 2038 or Everett until 2041.

In 35,000 responses to an online survey and thousands more e-mails and letters, "the message we heard was simply 'build light rail faster,'" Sound Transit board chair and King County executive Dow Constantine said recently.

So the agency is back with an improved version of ST3 that officials say will deliver light rail faster for the same annual cost to taxpayers. Citing a new financial analysis, Sound Transit is promising to borrow more money sooner, allowing it to shave years off some of the project timelines. The changes add $4 billion to the package and they improve timelines, add stations, and make an important change to Seattle's Ballard line. The highlights:

• A line to West Seattle would come online in 2030 instead of 2033, and the line to Ballard would be finished by 2035 instead of 2038.

• Instead of building light rail to Ballard alongside traffic on 15th Avenue, the agency would elevate the line through that area. That change would make that line more reliable and add about $150 million to the package. (Some want to go even further and build a pricey tunnel under Salmon Bay for this line, but the agency shows little appetite for that.)

• Stations at Graham Street in South Seattle and Boeing Access Road in Tukwila would be done in 2031 instead of 2036.

• The agency would build a new station at 130th Street in North Seattle after finishing light rail to Northgate, which is currently under construction. This is a big win for advocates in North Seattle, including new Council Member Debora Juarez, who represents North Seattle and has been adamant about this station. Juarez called the news "a giant step forward."

• In addition to light rail, ST3 would make some short-term improvements to Seattle bus service. With the changes, those improvements will now include Bus Rapid Transit on Madison Street, along with the city's Rapid Ride C and D lines.

• The new downtown transit tunnel through which the Ballard and West Seattle lines will run would be funded by taxpayers from all over the region. The agency's policy of "subarea equity" generally says taxpayers' dollars should be spent in the area where those taxpayers live. But Sound Transit argues the new tunnel will benefit the whole region because riders will use it to transfer lines.

• Light rail would arrive in downtown Redmond and Federal Way in 2024 instead of 2028—just a year after already funded extensions to Lynnwood, Bellevue, and Microsoft's campus in Redmond open. Service would reach Everett in 2036 instead of 2041, and the Tacoma Dome in 2030 instead of 2033.

You can read the full list of changes at SoundTransit3.org.

How, exactly, can Sound Transit offer all of that without increasing the $400 in new taxes per year the average household will pay if voters approve the plan?

Sound Transit officials say a new review of the agency's bonding program showed they can borrow more money sooner than they previously thought without endangering their credit rating. This new financial review was incomplete when the agency released its first package in March, so the financing assumptions were "very conservative," according to the agency's CEO, Peter Rogoff.

While the annual cost would remain the same under these changes, taxpayers won't be getting something for nothing. The taxes would last longer. Under any version of the ST3 proposal, projects would be done in 25 years, but taxpayers would keep paying off bonds beyond that time frame (and then continue paying for operations costs even after the bonds are paid off). With these changes, that payback would take a little longer. The agency does not yet know exactly how much longer, a spokesperson said. In any case, paying back those taxes will likely be combined someday with another light rail measure—the eventual Sound Transit 4—meaning we'll all be paying the new taxes far into the future.

The Sound Transit Board will vote in June on the final package to send to the November ballot. While improvements of just three or five years can be hard to get that excited about—light rail to Ballard is still 19 years out—the faster timelines will also improve the package's chances of passing, says Shefali Ranganathan, the executive director of Transportation Choices Coalition, which will run the pro-ST3 campaign.

"What we will be able to tell the public is that you'll see these projects open every few years," Ranganathan says. "That's a very big selling point."