Mayor Bill de Blasio reportedly got a taste of daily commuting life when his train to a speaking event was 20 minutes late.

In an email sent to staff Monday that erroneously included a New York Times reporter, de Blasio griped about "2 problems today" in the subject line, according to the paper. When he went above ground, his security detail had left "rather than waiting to confirm we got on a train," the mayor wrote to Deputy Inspector Howard Redmond, according to the Times.

De Blasio lamented how his team was unaware of the delays on the line, saying it was "knowable info. Had we had it, we would have avoided a lot of hassles," the Times reported.

The misfired email came at an inopportune time after transit advocates blasted the city's $125 million annual contribution to the MTA's five-year $32 billion plan to maintain mass transit -- the kind of work that could mean fewer major delays.

"Mayor de Blasio's experience shows that no one is immune to subway delays," said Nick Sifuentes, deputy director for the Riders Alliance, a grassroots transit group. "Service is getting worse for almost six million riders a day, but we know how to fix it: the City, State and the federal government need to fund the MTA's capital plan."

A spokesman for the mayor did not return request for comment, but a senior adviser, Phil Walzak told the Times: "The mayor holds himself to a high standard and always wants to improve his work, and the same is true of his staff."

On transit funding, the mayor's budget plan is a 25% hike from the Bloomberg years, but less than the amount the city contributed in the early 1980s, which would be up to $363 million a year in today's dollars, according to the city Independent Budget Office.

MTA chief Tom Prendergast, in a letter to a top mayoral aide, this week said the city should be kicking in up to $300 million a year, plus at least $1 billion to get the next phase of the Second Avenue Subway started.

Budget spokeswoman Amy Spitalnick said the mayor will work with the state for a long-term funding plan and that he will head to Washington to call for more federal transportation money.

"Mass transit is a lifeline for New Yorkers, especially for the working families, students, and seniors who need it most. That is why the City is increasing its funding for the MTA to the largest level of general capital support since 2000, fully meeting the MTA's request of $657 million," she said in a statement.