IN PORTLAND, righteous indignation looks a lot like NE Multnomah.

Cutting across the Lloyd District, the street features a newly revamped bike path, separated from traffic by planters and a stout layer of pale yellow paint. It's one of Portland's few "protected bike lanes," a breed planners and advocates say we'll need more of if the city is to reach its cycling ambitions.

It's also the type of thing that can make Portlanders appear torn in two. This is a city with seriously entrenched opinions about how its road projects are funded.

And so it was last week, when the Bicycle Transportation Alliance (BTA) courted controversy by taking on a notion that's been around for more than a century (seriously): That bike riders barely help pay for the very projects that benefit them.

In an infographic released Tuesday, November 12, the BTA contended cyclists actually pay well above their fair share. It's not a new claim—but, predictably, it sparked scads of online outrage, a dismissive column in the Hillsboro Argus, and curt protest by the Oregon Department of Transportation (ODOT).

Lost in all that drama, though, was this: Research suggests the BTA was largely right. And local transportation wonks point out the organization missed a more pertinent point: The savings from bike-related infrastructure has the potential to far outweigh its cost.

"I don't think they're wrong to try to make that case," says Elly Blue, a Portland writer and bike advocate whose latest book, Bikenomics, will be released next month. "But if you really want to try to drive the case home, there are bigger ways to do it."

The BTA's infographic relied primarily on three data points to make its case. First, a BTA-commissioned survey that suggested almost 90 percent of cyclists in Oregon and Southwest Washington own at least one car and, so, pay gas taxes and other "user fees"—like license and registration costs—that go toward road projects.

Observers, Blue included, find the survey dubious.

More problematic was the infographic's breakdown of the ODOT budget. In its initial release, the BTA said only 63 percent of the department's revenue comes from taxes and fees paid by motorists, with the rest flowing from other sources—like lottery proceeds and the state's general fund—that non-motorists also subsidize. A day after the graphic's release, the organization adjusted that to 78 percent.

ODOT, meanwhile, insists that roughly 93 percent of its budget is drawn from taxes and fees paid entirely by motorists.

"I'm not really sure what their objective was in publishing this document," says ODOT spokesman Patrick Cooney. "We could have helped them get it straight had they contacted us."

Lastly, the BTA said it would take 9,600 bikes to cause the road damage of one car. That drew protest from Commissioner Steve Novick, who oversees the Portland Bureau of Transportation (PBOT). He texted the Mercury to say: "Passenger cars impose minimal wear and tear on roads, according to our chief engineer. It's trucks, buses, and regular old weather."

But the BTA stands behind the (corrected) graphic.

"User fees aren't the entirety of the budget, regardless of where you draw the line," says Gerik Kransky, the group's advocacy director. "The main point is: Everyone pays."

Even if the argument was somewhat problematic in its specifics, it contains a kernel of truth. A growing body of research points out user fees alone aren't able to cover the cost of the nation's roads.

That's a pervasive myth.

And a 2013 study by Canadian researcher Todd Litman found big disparities in how motorists and non-motorists kick in for transportation projects. Litman estimated a cyclist who travels 3,000 miles a year likely overpays almost the same amount as a motorist who logs 10,000 miles a year might underpay.

That dramatic conclusion is likely less potent in Portland which—unlike many cities—relies on user fees and loans for the majority of its transportation budget.

But some observers say parsing these revenue streams ignores a larger point: Bike facilities have the ability to save massive amounts of money.

"I think BTA would be on more solid ground if they say that they deserve a break on road costs because they're saving us so much on health care," Novick says.

Blue concurs: "When you invest in bike infrastructure it's not even spending. It's an actual investment that actually returns money."

A Swiss researcher, Thomas Gotschi, who helpfully made Portland the subject of a 2011 study, drove that point home. He found investments of $138 million to $605 million in bike infrastructure could be leveraged to save:

•Between $388 million to $544 million in health care costs.

•$143 to $218 million in fuel

•$7 to $12 billion in human life (measured “value of statistical lives,” a common metric in transportation planning)

Of course, those savings are predicated on new bike facilities drawing increased use. Which brings us back to that snazzy NE Multnomah bike lane.

According to PBOT, bicycle commuting in the Lloyd District increased by 25 percent in the year after the lane was installed.