Hope for passing a measure to double Alameda County's transportation sales tax to a full cent dimmed Monday with the latest election results that left the tax increase trailing by more than 4,200 votes.

The Measure B1 sales tax increase was trailing with 65.79 percent in support -- short of the 66.66 percent required approval -- after the county counted more than 93,000 more ballots over the weekend.

The race isn't over because tens of thousands of additional provisional ballots are not yet counted.

But the totals released Monday include all ballots cast at the polls and nearly all mail-in ballots, minus a few still in various stages of processing because of damage or mismarking, said County Registrar of Voters Dave Macdonald. Provisional ballots are being processed now and will be finished in the next few days.

The percentage of votes favoring Measure B1 nudged up slightly -- by 0.41 percent, but transit officials were disappointed that they still have so much ground to make up.

"You can imagine this dampened spirits," said Tess Lengyel, deputy director for the Alameda County Transportation Commission, the agency that proposed the tax increase. "It's still not over, though. We are going to continue to watch the results until the counting is finished."

As of Monday afternoon, the measure was supported by 318,089 votes -- more than 4200 votes short of reaching the two-thirds threshold.

Measure B1, touted as relief for traffic congestion, would provide $7.8 billion over three decades for roads, freeways and public transit.

In other races:

Assembly District 18

Rob Bonta became the first Filipino to win a seat in the state Assembly by beating Abel Guillen, a Peralta Community College District trustee. The race for Assembly District 18 was close on election night. But mail-in ballots gave Bonta, an Alameda City Council member, a decisive win with 69,282 votes. That accounted for a little over 51 percent of the vote. Guillen received 66,407 votes, just under 49 percent. Assembly District 18 includes most of Alameda, San Leandro and most of Oakland.

Assembly District 20

Further South, in Assembly District 20, former Hayward City Councilman Bill Quirk was barely edging out optometrist Jennifer Ong in the race to represent a wide swath of territory, from Hayward to North Fremont. Quirk, a retired scientist, received 62,416 votes versus Ong's 60,884.

Oakland

The latest vote totals did not alter the landscape in Oakland where two City Council candidates retained narrow, but almost certainly decisive leads after the most recent ranked-choice voting tabulations. In District 1, Dan Kalb continued to lead Amy Lemley 52 percent to 48 percent. However, Lemley on Monday was not ready to concede. In District 3, Lynette Gibson McElhaney retained a 6 percent lead over Sean Sullivan, who has already conceded.

Berkeley

Voters narrowly rejected Measure S, which would have prohibited sitting on sidewalks in commercial zones from 7 a.m. to 10 p.m. The measure, which was supported by Mayor Tom Bates and merchant groups, was trailing by 1,583 votes. In a closer race, it appears that voters are also likely to reject Measure T, which would allowed for more development in West Berkeley. The measure is trailing by 440 votes.

Fremont

Councilman Bill Harrison continued to lead Steve Cho, slightly increasing his margin of victory after the latest batch of votes were counted. Harrison has 34.1 percent of the vote, while Cho -- who trails by 1,384 votes -- has received 31.9 percent. Councilwoman Anu Natarajan is third with 26.2 percent, Aziz Akbari is fourth with 5.5 percent and Linda Susoev has tallied 2.1 percent.

San Leandro

In the race for the District 2 seat on the City Council, incumbent Ursula Reed came out on top in ranked-choice voting. Reed had 50.96 percent of the ranked-choice votes; Morgan Mack-Rose had 40 percent.

The Measure L parcel tax, as of Monday afternoon, was within a percentage point of garnering the two-thirds votes needed to pass, with 65.93 percent in favor and 34 percent against.

San Lorenzo

In the school board race, Norman Fobert pulled 50 votes ahead of Jim Sherman for third place. In first place was Penny Peck and in second place, Helen Foster, with three votes separating them.

Castro Valley

Newcomer Charmaine Banther won third place, with 19.52 percent of the vote, over Kunio Okui, who had 18.43 percent. John J. Barbieri captured first place, with 26.25 percent, and Jo A.S. Loss was in second, with 19.72 percent.