I went out to do a couple hours on the bike since I had Washington's Birthday off. I ended up calling 911 three times, and walking home.
That's an exciting as it gets. The details are aa bit more mundane.-
Call #1: A mile south on Shermer, I pass 4 cars in a row going the other way with some metal in their tires. Then I see that there is a bunch of construction stuff that was all over the road. I waved cars to notice the junk and called 911 in Glenview. Some other cars stopped, and we had Shermer cleared by the time the police showed up.
Call #2: Two hours later, I'm returning and notice a water pipe in the parkway spewing out water. I've reported several of these over the years -- it's the type of thing you notice on a bike, but not in a car. I call 911 in Morton Grove, giving the address as 9xxx Shermer.
Call #3: When I get to the corner, I realize I'm on Harlem Avenue, not Shermer Rd, so I have to call them back.
About half a mile farther, I hit come piece of sharp debris that gives me an instant flat. I decided to walk the two miles home and change the tire where it's warm. I have mountain bike tires in the winter to avoid this problem, but if the object is sharp enough and has the right angle, a flat results no matter how thick the rubber.