OAKLAND — BART is pulling all the stops in an effort to let riders — and potential voters — know just how badly it needs to upgrade its transit system, and how it hopes to pay for it.

Last week, BART launched an informational website called “Better BART” (www.bart.gov/better-bart) aimed at educating voters about the transit agency’s proposed $3.5 billion bond measure.

And on Monday the agency used a BART email blast to promote the idea of a new train control system, which would be paid for in part by the proposed bond.

In both bases, BART stopped short of asking for votes. As a public agency, it’s illegal for BART to use public funds to campaign for any proposal or candidate appearing on the ballot, but the line between campaigning and “informing” is not always clear. Public agencies can’t say “vote for” or “support” or “cast your ballot,” with regard to a specific measure or candidate, according to the state’s Fair Political Practices Commission. But everything else falls into much grayer territory, said Jessica Levinson, president of the Los Angeles City Ethics Commission.

“There are very fine distinctions with discussing the merits of a measure and advocating for it,” Levinson said. “Outside of those really blatant examples, which are incredibly easy to avoid, that’s where the litigation arises.” The website, which features boldfaced slogans, including, “It’s time to rebuild,” and “Better BART, Better Bay Area,” is not telling voters how to vote, said BART spokesman Taylor Huckaby; it’s all about education.

“A lot of people are having a lot of questions about what the bond measure is … and what it means for BART,” Huckaby said.

Huckaby became the darling of national news media, when, in the middle of an evening weekday commute in March, a mysterious electrical surge damaged multiple trains traveling between two East Bay stations, causing massive delays and angering riders. As passengers took to Twitter to vent, Huckaby, acting as BART’s official voice on the social media platform, responded to people individually and promptly with what many observers called a candor uncommon in official government messaging.

During the Twitter hailstorm Huckaby was quick to cite the agency’s need to replace and restore much of its aging infrastructure, despite the fact that engineers had not yet identified the cause — and still haven’t.

The issue of failing infrastructure and the subsequent need to restore it is, however, the subject of BART’s proposed $3.5 billion bond measure. And the new website is Huckaby’s brainchild, he said.

BART paid NelsonNygaard Consulting Associates $18,500 to put together a detailed description of the proposed bond measure, but Huckaby said the “clunky” 27-page document is difficult for most people to understand. It’s also only available as a PDF on the agency’s website.

“It’s a pretty dense work of scholarship,” Huckaby said.

So, the agency invested $6,600, plus staff time, in the new website to better educate its ridership, said BART spokeswoman Alicia Trost. Under a tab labeled, “The Plan,” the agency offers bullet-point descriptions of work to be done in Alameda, Contra Costa and San Francisco counties and a link to another PDF that describes, in broad brush strokes, how the $3.5 billion would be spent.

In the lead-up to BART’s last big bond, the $980 million Earthquake Safety Program that voters approved in 2004, the agency spent roughly $352,000 for educational materials, according to records, memos, and e-mails obtained by this newspaper at the time.

The materials shed light on how the agency secured passage of the measure two years after voters had rejected a similar one. BART spent approximately $317,000 to target areas of voter opposition, however, legal experts said the agency acted within legal limits.

Voters may be prepared to invest in BART’s infrastructure if a January poll is any indication. BART hired Fairbank, Maslin, Maullin, Metz & Associates to gauge voter attitudes for a $4.5 billion, $3.5 billion, or $2.5 billion bond measure. The survey demonstrated that more than two thirds of voters indicated they would support a $3.5 billion or $2.5 billion bond, even after reading arguments against it.

Trost said the agency has already held more than 200 public meetings to solicit input from riders, advocacy groups, elected officials and others on the measure. The agency will present the plan to several of the board’s subcommittees next week, and the BART board is expected to vote on the measure June 9.

“We’ve been educating the public about our needs and plans and hearing from them what they need and hope for from BART,” Trost said.

Contact Erin Baldassari at 510-208-6428. Follow her at Twitter.com/e_baldi.