When riding in a car with other people, what's the word that's uttered the most?

It depends, of course, on your co-riders, the topic of conversation, the song that's playing or the podcast you're listening to, and where you're driving through. But one thing is as certain as a train whistle is loud: If there's a railway buff in the vehicle, every sighting of an engine, and every pass-by of a station, will be called out with enthusiasm.

Thus if "train!" is a word that's often trilled, with excitement, in your car, best take that car to Union Station on Saturday, July 15 for the Summer Train Fest. Or, here's an idea: Hop a train to Train Fest, which just happens to be at a place where a lot of trains go.

It's a free day, though do note that joining a tour of the Santa Fe 3751: 1927 Steam Locomotive is twenty dollars for adults and ten dollars for youths ages 5 to 18.

What's to do? There are a host of old-school, way-back train engines to admire, and some passenger cars, too. Fancy a trip on a 1950 passenger car that's been "fully restored"? Or a 1956 Pullman sleeper? Well, both will be stay put, but you can daydream, in your mind, what it might have been like to chugga-chugga through towns and by stream and field in such beautiful conveyances all those decades ago.

A Kids Zone is part of the event, which is no surprise, as young people are rather taken with trains. And by "rather taken" we mean completely into, as in train sets, train books, train TV shows, train everything.

Model trains, too, will be out for lookie-loo-ing, with model train pros from both the Los Angeles Model Railroad Society and the Pasadena Model Railroad Club on hand to chat, explain, and share your engine-awesome obsession.

And if that obsession is in full flower for you, note that merchandise, books, and other items related to the ol', heart-tugging toot-toot of train love will be for sale.

Also for sale: Eats, from food trucks, around the station's South Patio. Chomp away on something tasty while you daydream, again, that you're supping on a dining car that's moving through the desert by night.

Where to get your Event Passport — it's free — and your map to all of the doings of the festival? At the Union Station Information Booth. And if you're one of the first 1,000 people to arrive, you'll score a pay-nothing Summer Train Fest pin, too.

Everything starts at noon on July 15, so you'll have ample time in the morning to watch a train show, or read a train magazine, and begin to build the anticipation at home. For if the word "train!" instantly summons your attention, the notion of spending an afternoon among vintage cars and engines is all about enjoyable, can't-wait-to-get-there anticipation, for sure.