The Nov. 8 defeat of Measure 3-509, by a majority of 63 percent, left the county with a $17 million annual gap between available money and projected maintenance of the 1,400 paved miles in the county road system.
"We have simply been unable to obtain success yet," said Gary Schmidt, the county director of public affairs.
Proceeds from the tax of 6 cents per gallon would have been split 60 percent for the county — about $5 million annually — and 40 percent distributed to cities based on population. The tax would have been limited to seven years, and the county specified 47 projects on which it would have spent its share.
Multnomah and Washington counties, and about two dozen cities, have local fuel taxes in addition to the state tax of 30 cents per gallon. Voters rejected all 10 attempts throughout the state Nov. 8 to raise or impose such local taxes.
State law empowers the county, as one of Oregon's most populous, to impose a local vehicle registration fee up to the state maximum of $43 annually without an election. The fee is collected every other year.
But only one, Multnomah County, has done so at $19 annually to raise money for the now-completed Sellwood Bridge. Clackamas County imposed a $5 fee for the same project, but voters overturned it in 2011 before it took effect.
Washington County has approved a $30 annual fee, but it is delayed until mid-2018. If state lawmakers raise a specified amount of aid for the county through statewide taxes and fees in the current session, commissioners can suspend or rescind the local fee.
Voters rejected local fees in Washington County in 2014, and in Lane County in 2015.
Clackamas County's road fund consists of its shares of state fuel taxes, weight-mile taxes on trucks, and vehicle registration fees. State law generally bars use of property taxes for the road fund. Federal timber payments, once a key source of money, have disappeared.
Newly elected Commissioner Ken Humberston said he is willing to proceed with a local fee, proceeds from which also would be split 60-40 between the county and cities.
"We have a responsibility to the infrastructure of this county and the next generation" not to leave its roads in bad shape, he said.
"In the final analysis, this is our decision to make. When the day comes when I leave this board, I do not want to leave an infrastructure financial mess."
But Commissioner Paul Savas said such a decision could trigger not only a move by opponents to refer it to the ballot, but also doom prospects for future funding.
"We need the voters to get to the finish line, and I am not willing to betray them," Savas said.
Voters in the May primary, by a 68 percent majority, approved an advisory measure to encourage commissioners to seek "voter-approved funding" for road work.
Board Chairman Jim Bernard, who was a commissioner before his elevation Nov. 8, said that vote confused some people who thought they were voting on an actual source of funding.
"I know why it (Measure 3-509) failed — nobody wants to pay the tax," said Bernard, who as mayor of Milwaukie led a successful effort by the city council in 2007 to establish a city fuel tax. (State law was changed in 2009 to require voter approval of such taxes.)
Savas said a key to future voter approval lies in a political action committee to campaign vigorously for whatever funding measure emerges. The county cannot engage in such advocacy under state law, but Savas said business interests can do so.
"This has always been a tax-averse county," said Commissioner Martha Schrader, who was in office when voters rejected another funding measure more than a decade ago.
But the gap between available money and projected needs has grown from $13 million annually back in 2007 to $17 million today.
"Every year, every day, it costs us more money," Bernard said.