JANA JARVIS, president of Oregon Trucking Associations, Inc., keeps a recording on her phone. She'll play it for you if you ask.

The file is a voicemail message City Commissioner Steve Novick recently left for one of her coworkers. In it, an audibly piqued Novick says he could persuade voters to tax truckers more than $30 million a year to pay for Portland streets, if a 10-cent-per-gallon gas tax on the May 17 ballot fails. The money's got to come from somewhere, the commissioner suggests.

"I was threatened," Jarvis said recently.

Well. Kind of.

Novick's message was a response to a fundraising plea Jarvis' lobbying group sent out to members this month. The email argued that if truckers defeat the gas tax—which would apply to lighter vehicles only—then Portland City Hall would be unable, as a matter of fairness, to force truckers to pony up for road repairs as planned.

"I am even more convinced that the only way to stop this nonsense is, in fact, to kill the gas tax," Jarvis wrote in the email.

As it stands, truckers will likely pay a small fraction of money officials are seeking for road repairs. The four-year gas tax Portlanders will vote on next month would raise roughly $16 million a year. The city's been looking at ways to rake in around $2.5 million year on top of that from heavy trucks (26,000 pounds and up), which can wreak havoc on city streets.

So Jarvis' email set Novick off. In his voicemail, the commissioner said he'd have little trouble getting voters to enact a 15-cent-per-gallon tax on bulk diesel sales—a so-called "load-fee" that had been one of the options for getting money from trucks. That's roughly 1,400 percent higher than the city had proposed, and could've meant a $1,500 charge for city coffers every time a tanker truck filled up in Portland. It could also have raised more than $30 million a year.

Novick suggested he didn't want to do that—"I'm trying to be fair here"—but would if necessary.

I wanted to know if the voicemail was an idle threat. Novick, who's earned his share of battle scars pushing for roads money over the last two-and-a-half years, stood behind it.

"Any pollster would probably say voters are more likely to approve a tax on diesel, which most of them don't use, than on gas," he told me.

If he's forced to—on the heels of what would be just the latest in a decade-long string of failures to score millions for city streets—Novick says anything's on the table.

"I know there are objections, but we need to have something," Novick says.

That "something" will not be the 15-cent-per-gallon fee Novick threatened—at least not yet. On Tuesday afternoon, he unveiled a new "heavy vehicle use tax" proposal that would be more fair to truckers, and charge them about $2.5 million a year for their damage to city streets­—not $30 million.

Don't expect that to sway the truckers, though. Threats or no, they don't want to pay Portland for its roads.