One time a couple of years ago, I had a rental car on the U.S. East Coast. I didn't want to pay the rental company's surcharge for toll billing, so I paid cash at every toll booth. At almost the very end of my stay, I went across a stretch of toll road in upper Manhattan, and the road had no toll booth. Even though I had charged only the one toll, I had to pay the rental company a surcharge for every day of the three-week period I rented the car. Twenty-five bucks for a $1.00 toll.
Damn. I wish they had a national toll-paying system, maybe with a chip embedded in my car instead of the plastic box that the velcro doesn't hold on my windshield. There are some interstate toll payment agreements, but too few.

-Joe-