NO.

A couple of weeks ago Hallie and I were on our way to pick up Will from a practice at school. We were stopped at a red light when Hallie suddenly exclaimed, "OH MY GOSH! That's the creepiest thing I've ever seen!" She then added, "S...L...O...W...L...Y turn your head to the left, Mama. Or don't."

No. NONONONONO. H-E-Double Hockey Sticks NO.

I handed Hallie my phone and asked her to take a picture, which she did. The driver - who looked perfectly normal and pleasant - noticed her taking pictures and smiled and waved, in a completely normal and pleasant way. And when I finally looked again, he smiled and waved at me too.

As we investigated further, we discovered that the van's passenger was not a person dressed up in a clown ensemble and mask, but a fake clown constructed out of a stuffed jacket and a mask attached to something shaped like a head. We couldn't decide if this detail made the clown more or less creepy... 

"Moral" of the story? Keep your eyes on the road, and ONLY the road.