San Francisco and Los Angeles are both building subways below their downtown cores. And now both cities’ projects are over-budget and late. As Matier & Ross report in the San Francisco Chronicle:

San Francisco’s already behind-schedule Central Subway won’t be completed until 2021, more than a year later than the city insists the line will be ready, according to a new report by the big dig’s main contractor.

Construction giant Tutor Perini Corp. also says the $1.6 billion project is running tens of millions of dollars over budget.

Adding insult to injury, the former head of the agency that oversaw construction of the Transbay Transit Center, which went horribly over budget, is apparently lobbying the city for more money for Tutor Perini. The delay means the line won’t be able to serve the new Golden State Warriors arena for the first two seasons. For their part, city officials seem to think the contractor is bluffing to get more money. Either way, it’s not a good sign.

Meanwhile, in Los Angeles, the downtown regional connector light rail line is also in trouble, as Laura Nelson reports in the Los Angeles Times. The new opening date is now December 2021, a year later than the agency’s original target date of December 2020. Its $1.75-billion budget is now 28% higher than originally forecast.

Residents in these two major cities are now spending a better part of a decade watching these relatively short rail lines get built, at increasing taxpayer expense. While I’m sympathetic to the challenge of building under old urban environments, I wonder how much of these challenges should have been foreseen. It’s almost a joke at this point that elected officials over-promise on cost and timelines to sell new rail lines at the outset. But it would be nice to see those those promises actually come true for once, especially for transit projects as important as these.