The United States, as a whole, does not have a well-developed public transportation system. If the car is a symbol of freedom, a public bus is just about the opposite. Bus or train schedules rarely seem to follow work or errand needs. The systems are often slow and inefficient.
But from the standpoint of reducing transportation-related pollution, using public transportation is one of the most effective and immediate changes the country can make.
According to PublicTransportation.org, public transportation -- mainly buses and subways -- saves about 37 million metric tons of carbon dioxide annually. Additionally, if an individual switches a 20-mile (32.2-kilometer) daily roundtrip commute to public transportation, their annual CO2 emissions will decrease by about 4,800 pounds (2,177 kilograms) per year.
Combining an increase in public transportation with better road engineering, land use and other factors could help reduce transportation-related pollution by more than 20 percent.
Private concerns can also help with public transportation. Companies are often encouraged to provide a shuttle bus for their employees or post ride-share boards. Car cooperatives are making in-roads in the United States. These services allow a member to rent a car from a central location and pay a small fee for use. The system is ideal for inner-city dwellers that only occasionally need a car, allowing them access to a vehicle without needing to buy one. By using public transportation for their primary needs and a regular car for the odd trip where it was necessary, one Swiss study indicated car cooperative owners drove more than 60 percent less than they would have if they owned a car.