A major American city faces a hotly debated referendum to expand its road and transit network. The local business community is solidly behind it, claiming that passage is vital to the region’s economic competitiveness. Meanwhile, a motley group of community organizations, including the state chapter of the Sierra Club, are opposing the measure.

The reaction to this opposition from proponents is fierce. “There is no Plan B!” they loudly proclaim. “This is the only chance we’ll have for a generation!” others cry. “The political climate won’t allow anything better!”

This may sound like Atlanta today, but the city in question is in fact Seattle, and the year is 2007. That city’s “Roads and Transit” referendum, an awkward mixture of popular transit projects and sprawl-inducing road construction, would eventually go down to defeat at the polls.

Despite predictions that another chance was a generation away, a Plan B was put to voters the very next year, this time focused entirely on expanding and enhancing the region’s SoundTransit rail and bus network — without the massive road expansion. The 2008 “SoundTransit 2” initiative passed handily, and Seattle is now actively building out an ambitious regional transit vision.

Seattle is hardly alone. Voters in Charlotte, Denver, Los Angeles and St. Louis have all recently approved ballot measures focused entirely or primarily on transit. These cities span a wide range of geographic locales and political climates, from the Rust Belt to the Sun Belt, red states and blue states.

There is good reason for cities to embrace transit. It’s increasingly clear that the workforce of the 21st century desires walkable urban living instead of being forced to drive everywhere. One recent study found that from 2001 to 2009, the number of miles driven by young Americans (age 16-31) fell 23 percent, while miles traveled on transit increased 40 percent and bicycle trips increased 24 percent. Georgia needs to attract these workers in order to attract their 21st century jobs.

Meanwhile, Atlanta’s proposed response to this national trend — the July 31 T-SPLOST — remains stuck in the past. While the tax would fund initial segments of some popular transit projects like the Beltline, every new track-mile of light rail built would be matched by 16 lane-miles of road expansion — enough asphalt to cover Turner Field more than 200 times. Despite talk of the tax “transforming” metro Atlanta, in reality this plan is largely a business-as-usual approach.

Our peers understand that the era of sprawl-fueled economic growth is over, and that providing alternatives to traffic must be the focus of their transportation future. Which course will Atlanta take? Will we simply rev up the old sprawl machine one more time, or hold out for a vision that truly puts Atlanta at the forefront of 21st century cities? On July 31, voters have that choice.

Colleen Kiernan is director of the Georgia Chapter, Sierra Club.