PERHAPS no single act could have prevented last week’s bus shooting in downtown Seattle. But additional training and stable funding for cash-strapped King County Metro Transit can help to keep drivers and passengers safe in the future.

One bus driver was shot and survived. A driver on a second bus with passengers ran for cover. Police fatally wounded the gunman, a homeless 31-year-old felon with a history of mental illness.

On July 31, more than 40 business leaders wrote a letter to the city demanding immediate action to curb a recent spike in violent crime. A Seattle Times analysis recently found violent crimes in the downtown core — including assault, murder, rape and robbery — have held steady since 2008.

Though the bus shooting is considered an anomaly, veteran operators say they lack the knowledge necessary to deal with riders who show symptoms of mental illness.

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King County Metro General Manager Kevin Desmond says his agency coincidentally started offering refresher courses last week to drivers, with an increased emphasis on how to detect and respond to passengers with “invisible disabilities.”

Metro can afford to make that training available only on a rolling basis to Metro’s 2,700 drivers, or once every three years, Desmond said.

Learning best practices is critical for operators who wear multiple hats (driver/fare collector/first responder). Their job requires direct contact with every segment of Seattle’s population, including the few who might pose a risk to public safety. For now, county officials report assaults on drivers are at a record low.

Budget-caused disruptions to routes and increased fares can exacerbate erratic behavior among passengers. Metro has increased fares four times since 2008 and is on the brink of cutting service by 17 percent in 2014 after a two-year vehicle-congestion fee expires. Expect other areas of the budget — including driver training — also to face deep cuts.

Last week’s Route 27 shooting should nudge state lawmakers into giving county leaders authority to put a local-option tax on the ballot.

Voters have a right to decide whether they want to contribute resources to help keep Metro a safe and affordable option for riders.