What do the carpool for the environment?

I need statistics on carpooling benifiting Environment if anyone has any suggestions.

If you carpool with one other person, you in theory only halved its collective emissions and took a car off the road. If you carpool with 3 other people that you just cut emissions by 75% and took 3 cars off the road. However, used car is a bit more at either pick up other people carpool or if you reply to a meeting place, other drivers are also likely to lead to this meeting place if emissions are not cut that drastically cut. But it removes cars from the road commuting Then, again in theory, if enough people's car pool, it accelerates the movement which will also be given to the environment (fewer cars idling away in traffic jams blocked).