Slugging etiquette?

I was listening to NPR's Car Talk this weekend and learned about sluggers. Apparently in big cities that have High Occupancy Vehicle Lanes (HOV), people wait by the entrance to the highway to be picked up by cars. Call it fraud but it's a win-win: The pedestrian gets a ride to work and the driver gets to take the HOV lane (you need a certain number of occupants in your car to take the HOV lane or you get a ticket).

It's called slugging.

The slugger who called Car Talk went on to say there was an etiquette to slugging: You don't talk unless being talked to. Boy, do I wish that applied to people in airplanes! Here are more rules from Wikipedia:

• Drivers are not to pick up sluggers en route to or standing outside the line, a practice referred to as "body snatching".
• A woman is not to be left in the line alone, for her safety.
• No talking unless the driver initiates conversation.
• No eating, smoking, or putting on makeup.
• The driver has full control of the radio and climate controls.
• No open windows unless the driver approves.
• No money is exchanged or requested, as the driver and slugs all benefit from slugging.
• Driver and passengers say "Thank you" at the end.

This Website explains how it works in DC:

The system of slugging is quite simple. A car needing additional passengers to meet the required 3- person high occupancy vehicle (HOV) minimum pulls up to one of the known slug lines. The driver usually positions the car so that the slugs are on the passenger side. The driver either displays a sign with the destination or simply lowers the passenger window, to call out the destination, such as "Pentagon," "L’Enfant Plaza," or "14th & New York." The slugs first in line for that particular destination then hop into the car, normally confirming the destination, and off they go.

No money is exchanged because of the mutual benefit: the car driver needs riders just as much as the slugs need a ride. Each party needs the other in order to survive. Normally, there is no conversation unless initiated by the driver; usually the only words exchanged are "Thank you" as the driver drops off the slugs at the destination.

There doesn’t need to be any discussion about the destination , such as giving directions, because the drop-off points are generally understood.