BART officials claim they reached peace with their workers. In fact, they bought them off — at taxpayer and rider expense.

On its face, the latest labor deal seems innocuous: It extends the current 2013 contract for another four years with salary increases at roughly the current cost of living.

But that lacks context. BART officials gave away the store in 2013. The new extension, to 2021, layers onto the earlier deal, further inflating salaries without paring back sweetheart benefits.

And, in a detail General Manager Grace Crunican didn’t mention during her public announcement Monday, BART negotiators gave up any hope of saving money by insisting workers contribute their fair share to their pensions.

BART can’t afford this deal. Projections show a $400 million shortfall in the district’s operating budget over the next 10 years. The new contract will dig the hole $77 million deeper.

BART officials were under political pressure. The possibility of another strike next year, when the 2013 contract was due to expire, threatened to derail the transit agency’s planned $3.5 billion bond measure on the November ballot.

Against that backdrop, Crunican on Monday stood flanked by labor leaders and declared the new deal would bring riders “the certainty of no strike, no service interruption, unless it’s planned, between now and 2021. It’s five years of labor peace.”

But if she was trying to convince voters that BART could be fiscally responsible with public money, she blew it.

BART officials once again failed to determine if they were paying too much. They should have conducted compensation surveys comparing BART’s payouts for wages and benefits to similar jobs at other metropolitan transit agencies across the country.

They should have used those numbers, adjusted for regional cost-of-living differences, as the basis for negotiations, as they did in 2009. That survey showed BART paid at or near the top in the nation, even when adjusted for regional cost of living.

But in 2013 and this time, they flew blind. They don’t want voters to know how far beyond the norm BART might be. Apparently, they don’t want to know themselves.

What we do know is that the 2013 contract and the new extension will increase salaries 29 percent over eight years.

Then there are the benefits, of which pensions are the biggest. To fund them, BART’s share in 2017-18 will be 18 cents on top of every dollar of salary. The share for most workers should be 7 cents, but BART will pay 3 cents of that, too.

With the Obama administration attempting to block Gov. Jerry Brown’s statewide pension changes, there are legal questions surrounding the retirement benefits for transit workers hired after 2012.

So, when announcing the new labor deal, Crunican said discussions of increasing BART employee contributions to pensions will be postponed until the litigation is resolved.

She didn’t mention that the deal includes provisions assuring workers that if they pay more for pensions that will be offset with another salary increase to ensure the effect is “cost neutral.”

There was also no attempt to scale back other benefits and contract provisions such as:

Retirement savings account: On top of pensions, workers also receive BART-funded retirement savings accounts. The annual district contribution for each worker is $1,869 plus 1.63 percent of salary.

Health care coverage: Workers and most retirees receive full family health care coverage for $138 a month, regardless of the number of dependents.

Work week: Train operators, station agents and other members of the Amalgamated Transit Union work only 37.5 hours per week, not 40.

Leave time: BART workers receive up to six weeks paid vacation annually, of which they can cash out a week each year. They receive 12 days of sick leave, and can apply unused portions toward their pension service credit or cash it out. Plus they receive 13 paid holidays.

Annual bonuses: Workers receive $1,000 annual bonuses for each year that ridership exceeds projections by 2 percent.