It occurred to me as I was driving around today that there's a bunch of elevated train tracks in Steelport, (you can see some from the helipad of Saints HQ, for example) but I don't think I've ever ridden a train or even seen one anywhere, and I don't remember seeing any train stations. I'm not even sure I know where the tracks go, except in a big circle.
Are there trains in Saints Row 3? Can I ride in or hijack one, if so? Where do they go?
There are no active trains, either ground or elevated trains. There are disabled trains on the ground in a couple of places (so beware if you are riding a motorcycle along the tracks), and there are disabled trains on the elevated tracks as well.
I've made a complete circuit of the elevated tracks on foot, and there's no way for a train to run on them: at one point, one of the wrecked trains blocks the track in both directions, requiring you to make a physically-impossible jump to continue the circuit (jumping out and steering yourself back onto the track). There are no signs of activity on any of the trains, although you may wish to investigate at least one of the train cars on the ground. (Perhaps there's something inside it?)
There are no trains listed on the Saints Row Wiki article on Saints Row: The Third, while there is an article for the El Train from SR1 and 2. This is obviously not conclusive, though.
Anecdotally, I accidentally jumped a car on top of the train tracks one time, and did not see any trains running on it. Again, this is not conclusive, so take that with a grain of salt.
There are trains on the game but they are crashed and rusted in certain areas.
For some very odd reason, trains were removed from this game, despite being in the last two games..
If you jump from the HQ helipad forward and parachute ontp the tracks, the bars look as though they couldn't even support a train, they're all bent.
