Snow, gravel and training tires.
Training tires. Those words mean different things to different people. For some, it means old race tires. This makes the least amount of sense unless your training tires stay on the trainer or rollers. Otherwise, those tires are probably pretty thin to begin with and have no puncture protection. And since they've been raced on, they're even thinner. That might work in other areas of the country, but not here in the Pacific Northwest. The rain keeps the shoulders and bike lanes full of debris. No place for thin tires. And this winter has brought us something extra special - snow. Portland has no real infrastructure to handle snow removal. Its answer is gravel. Lots of gravel. Eventually that gravel gets swept from the roads to - guess where - the shoulders and bike lanes. Pretty much making them unrideable or a flat waiting to happen.
So, another option is a "training" tire. To me, that used to mean a cheap tire. One that was heavy, had a steel bead, and thick rubber. They ride terribly, though, and don't always last that long. And cheap means no puncture protection layer. Now training tires are super fancy, culminating in the current version of the Continental Gatorskin. Not that heavy, with decent ride quality and all sorts of puncture protection. All that technology is pretty expensive, though, and I still wind up flatting more than I'd like to. And I buy them in 23mm because they look like race tires and I want to feel fast when guys lay it down on training rides.
This year I decided all of this was silliness. Due to my work schedule and baby, much of my riding will be alone and I shouldn't worry about being super fast on a training ride - going hard is going hard, even if the mph doesn't reflect the effort! And my work commute is nice, but not exactly rural country roads. It's mostly a step down from a local highway. Good shoulders and bike lanes, but still lots of traffic kicking debris to the side. So I bought touring tires.
Touring tires are meant for high mileage, and for handling the worst roads, paved or unpaved. Mostly the purview of Rivendell and recumbent folks, but perfect for our current riding conditions. They are heavy. Very heavy. And supple as a brick. But the ones I got are supposedly unflattable. That's right - the Schwalbe Marathon Plus is advertised as unflattable. Most of the reviews I've read seem to agree. Did I mention they have a reflective sidewall? Yep - that cool. And a steel bead that is amazingly difficult to work with. But who cares? Once they're on, I hope to not change a tube for a very long time. Initially I put the 28mm one on my fixed gear/ss cross bike. It's been perfect. I steer towards the gravel just for fun and they haven't picked anything up yet. If you don't pump them to max psi they ride ok and you still don't have to worry about a puncture or pinch flat.
I was hooked and ready to make the switch on my fendered training/rain bike (training season and rain season are the same in Portland). A fat 28mm tire wouldn't fit with the fenders and even I would agree that it's a bit obnoxious on a road bike. Luckily, Schwalbe makes the Marathon Plus in a 25mm width, too. FYI, it's a very big 25mm - there is a tread, and it is tall, not just some weak, gimmicky siping. There is a tiny bit of rubbing on the front fender which I can't seem to fix, but I figure that a millimeter off the top of this tread isn't going to hurt me.
So, you might pass me when you are on the rivet during an interval this winter even though I try to keep up, but I might be passing you back as you fix another flat on the side of the road.
And of course, I'll have some silly thin and ultra-lightweight tires on for race day. I hope it helps!

