The amount of Car Usage in a nation measures how many miles per year the average household travels by car. Excessive car usage is a universally negative statistic, as it reduces Air Quality by up to 22% and increases CO2 Emissions and Oil Demand by up to 50%. Car usage also affects the number of Motorists, with high usage leading to more motorists and low usage leading to less. It also increases Traffic Congestion and Petrol Tax and Toll Road income. It has a detrimental effect on the Environment. It contributes to the Asthma Epidemic.