your point is taken generally, for sure. I don’t like UPS trucks parked in a bike lane or exemptions from environmental or zoning laws. Howerever, if the specific purpose of a congestion tax is to remove completely unnecessary traffic from a downtown area, a plumbers’ truck doesn’t seem like a good target of this effort. A plumber would be hard-pressed to do their work without their truck, whereas private citizens can commute about without passenger cars.