[Koblenz]

Tolls would vary depending on time of day and number of passengers.

Congestion based tolls are a great idea. Roads have a limited supply (only a certain number of cars can fit before a jam up, which is in effect a shortage, occurs).

However, it makes no sense to base the pricing on the number of passengers in the car. A car with one occupant uses the same amount of pavement as a car with four occupants. The passengers can of course split the toll, but it doesn't make sense to give them an additional discount.

With congestion based tolls, people who really value their time and cannot shift their demand of road space to another time pay the most. The HOV pricing makes no sense here.

[MinnesotaLibertarian]

However, it makes no sense to base the pricing on the number of passengers in the car. A car with one occupant uses the same amount of pavement as a car with four occupants. The passengers can of course split the toll, but it doesn't make sense to give them an additional discount.

I think you're missing the point. The idea is to encourage people to car pool. Four people in one car takes up less space than four people in four cars.