Got an MTA Web Advisory in my in-box late Friday urging Metro-North riders to consider not bringing their brand-new copies of Harry Potter and the Deathly Hallows on the train in the coming weeks. You see, owing to the hardcover book’s 750-odd page heft, large numbers of them slow down the trains, which as we all know, don’t need much assistance in being slow.

“We’re not telling people not to bring their book of choice on the train,” MTA spokesperson Bob Ogden says. “We’re simply asking them to consider waiting a few weeks to start the new Harry Potter so we can stagger the number of Potter books on each train.”

Ogden notes that every 100 copies of the 2 1/2-pound Deathly Hallows, which was released just after midnight last Saturday, weighs “about as much as two typical female riders.” He also points out that every Potter release causes people to break out the older books in the series, meaning more giant books on the train.

I’d finish with a Potter-esque quip here–something about Dumbledore, or quidditch–but I haven’t read the books.