Whenever I took the T (the subway system in Boston), I always tried to sneak a peek at what other commuters were reading. I’d try to read the books’ spines without the other passengers catching me. However, I’ve come to notice that more and more commuters (myself included) are on their phones these days, whether they’re listening to music, texting or updating social media. Or maybe they’re even using their phones to read. Whatever the reason, I’m finding that physical books are becoming more of an infrequent sight.

However, bibliophiles would have been pleased with Chicago’s subway this past October. During Chicago Ideas Week, which ran from October 12–18 this year, the city’s train system (the CTA, more commonly known as the “L”) participated in an initiative called Books on the L. With the goal of encouraging reading, hundreds of books (some of which were donated by Open Books, a nonprofit that promotes literacy in the Chicago area) were placed on the city’s trains for commuters to enjoy.

All that week, the L turned into a library of sorts, emphasized with the slogan, “Take it. Read it. Return it.” Each book was also marked with a bright yellow Books on the L sticker, making it easy for commuters to locate the books. Passengers could enjoy them as long as they were on the train, but were expected to leave the books behind at their final stop for the next readers. The books were selected from all sorts of genres and many were authored by individuals who appeared as guest speakers during Chicago Ideas Week, such as Martine Rothblatt, Scott Shane, Michael Strahan and Senator Claire McCaskill. The train’s transformation certainly caught the attention of social media—the hashtag #BooksOnTheL was used to spread the word about the initiative and to allow commuters to share what they read.

This was not the first year that the L train turned into a temporary library—Books on the L first debuted in 2014 during last year’s Chicago Ideas Week, which happens annually in October. So if you missed out on Books on the L this year, there is a chance it will be happening again during Chicago Ideas Week 2016 (which, by the way, will be occurring from October 17–23). Other subway systems have also taken part in similar initiatives, such as the London Underground and the New York City subway system. Perhaps, then, a mobile library will be coming to a transit system near you. I’ll personally be hoping that Boston will be the next city to take on this trend.

Did You Know?

The CTA is typically referred to as the “L,” which is short for elevated (even though only parts of the train system are elevated today). However, there is often the debate over which way to spell this abbreviation: the “L” or the “El”? It appears to be a matter of preference, but as of 2012, the Chicago Tribune’s stylebook deemed the “L” to be the acceptable spelling.