I put this under class A as I believe those driving Motorhomes ( especially longer heavier w/tag axles) would be paying much higher tolls than fifth wheels or travel trailers, and perhaps more likely ...
You go up or down I-95 between DC and Richmond and you will be glad to pay the tolls for the express lanes and look at those in the regular I-95 sitting for hours while you zip along. But you also need to time that right as they only go one way--North in the AM and South in the PM.