Pedestrian, n. The variable (an audible) part of the roadway for an automobile.
There are two kinds of pedestrians – the quick and the dead.
The only people here are the quick and the dead. (Commenting on New York City traffic)
A pedestrian is a man in danger of his life. A walker is a man in possession of his soul.
Automobile, n.: A four-wheeled vehicle that runs up hills and down pedestrians.