Your first book, Goodnight, Goodnight, Construction Site, was on the New York Times bestseller list for nearly five years. How did you get the idea for it?

My little guy was born truck-obsessed. When it was time for him to settle in at night, he always picked truck books. But instead of being soothed to sleep, he got really wound up. So after we closed the books, we’d imagine a construction site going to sleep. I’d say, “I think I can see a dump truck dumping out its last load of the day. He’s putting up his gate and turning off his lights.” One night I was putting my own head on the pillow, and I thought, Oh my gosh, this might be a book.

Your new one, Three Cheers for Kid McGear!, is your fourth in the series but the first with a female protagonist — a skid steer.

When my first book came out, I’d see fields and fields of 4-year-old boys at events. But now it’s pretty mixed. I’m excited to offer those little truck-loving girls something.

How do you do your research?

I have a friend who owns a ready-mix concrete plant, so I consult with her a lot. Once I called in the middle of a workday and said, “I have some questions about what trucks might want for Christmas.” And she was like, “Sherri, I’m going to need to call you back.”

You’ve mentioned on your blog that your own childhood was kind of rough.

My mom was always looking for something else. She was just naturally attracted to excitement. She was married four times. Going out, drinking, smoking, bar life, men — they were really a draw for her.

I’m assuming there must have been books, though?

My aunt was a schoolteacher. When I was in third grade, I don’t know how she did it, but she sent boxes and boxes of books to our house. Up until then, I never remember my mother reading to me.

And now you read to kids all the time.

I truly, truly, truly love being with them. Last year I did a reading in Winnetka, and we got to the part where Dump Truck is snoring so loudly that there’s a man yelling because he’s trying to sleep. A little boy probably 3 years old was sitting crisscross-applesauce in his little overalls, and he held himself and said, “I just wuv that pawt!”

When you’re driving and you hit construction delays, are you a little less irritated than the rest of us?

If I can see the construction, I watch and learn things. If I’m just sitting in traffic, I’m as angry as everyone else.