Mayor Bill de Blasio made big news this week when he complained that his staff really messed up when they put him on a subway to the TechCrunch confab.

His missive to his underlings wound up in a Times reporter’s inbox and revealed something that has MTA critics demanding to know: Does the mayor have special access to train delay info.

“We waited 20 mins for an express only to hear there were major delays,” de Blasio wrote in the email, the Times reported. “This was knowable info. Had we had it, we would have avoided a lot of hassles.”

Knowable info? Really. How?

Among those wanting to know how delays are knowable is Times reader Vivianne Kurzweil, who in a letter to the editor, writes: “Mayor de Blasio, can you please share your M.T.A. contact information with all subway riders so that we, too, can get this “knowable info”?”

It turns out, his potential “knowable info” is something Kurzweil and the rest of us can’t get -- and de Blasio even alluded to it in the can of whoopass he opened on his minions.

“The NYPD Transit Bureau staffs our Rail Control Center 24 hours a day. If the mayor's detail contacts the Transit Bureau, they can surely have a more detailed discussion about how the trains are running” the MTA’s spokesman Adam Lisberg told @metronewyork.  

Lisberg adds: “All our subway service status info -- the “widget,“ as we call it, which you see on our homepage and on www.311nyc.gov -- is updated instantly from our Rail Control Center.”

 He also noted that info for the public will get better if the state agency gets -- you guessed it -- more money.

“We have put a lot of time, energy, personnel and money into improving real-time communications with our customers to instantly alert them to trouble. The next big step forward will be to install countdown clocks on the lettered subway lines, which is why we're beating the drum so loudly to fully fund the $14 billion gap in our Capital Program,” he told Metro.

“At the moment, we don't have enough money to keep pace with basic maintenance and replacement for the next five years, much less to undertake important improvements like countdown clocks. We need the city, state and federal governments as well as the private sector to invest in the MTA network to keep the entire region moving and informed.”

Earlier this week, Metro reported that the MTA was leaning on City Hall to up the amount of tax money it sends the agency.

De Blasio had other alternatives a lot of us don’t and was miffed that that other alternative, his taxpayer-funded vehicle, drove off.

“The detail drove away when we went into the subway rather than waiting to confirm we got on a train,”  he sniffed.  “We need a better system.”

(Here’s an idea: How about an Uber or a yellow cab next time?)

He urged his team to coordinate future travels with the Metropolitan Transportation Authority, “or at least with nypd transit.”

“Let’s cross-check our info with them when I take the subway,” de Blasio wrote. “This is a fixable prob.”

 Follow Metro's Editor-at-large John A. Oswald on Twitter -- @nyc_oz.