Flat tire patrol: population frugality

I was walking to work the other day and spotted a car with a flat tire. Firstly, the flat tire can have dangerous consequences, especially if it had blown on the highway and potentially caused one or more collisions.

But... thinking frugally.... what if we kept an eye out for flat tires in cars that drive by? We could save gas for others, eventually reducing our carbon impact on the environment, and potentially decrease consumption? Personally, it's about the safety of the passengers in others' cars, but if we did this as a population (i.e. kept vigilance for people with flat tires), we could save our society a lot of gas.

Just some random musings.