If you want to limit congestion, price congestion.
Don't limit taxis, the right to drive people, the right to drive a car ending with a particular license plate number, or the amount of fuel available (all have been tried to reduce traffic) -- just make the roads themselves cost more when there are more cars on them, and make the roads cost less when there aren't.
Don't limit taxis, the right to drive people, the right to drive a car ending with a particular license plate number, or the amount of fuel available (all have been tried to reduce traffic) -- just make the roads themselves cost more when there are more cars on them, and make the roads cost less when there aren't.