This handy chart is from the Michelin Tire Handbook found <HERE>.

It shows in an easy to understand chart showing what kind of acceleration and stopping distances could be

expected with different types of cars.

For a car the weight of the Marmon, the driver should expect a full stop from 50 mph to take 8 seconds.

Not bad... unless you actually time it:  EEEEK!  There is a dog/hog/child/beaver in the road!  Screeeeeech one Mississippi, two Mississippi, three Mississippi, four miss-THUMP-THUMP, five Mississippi, SIX Mississippi, SEVEN Mississippi, EIGHT Mississippi, FULL STOP!  Secure the hand brake and run back to help whatever you hit.  

Driving a fast car was pretty dangerous to everyone and everything around it.  This was BEFORE they started the

"Jay Walking" campaign and people just walked willy nilly around the streets because horses made enough noise and were slow enough to get out of the way.   Thousands of people were being killed every year and there was serious campaigning to stop allowing the rich people to drive these killing machines on public streets.

The Jay Walking campaign saved the automobile hobby and the auto eventually became a necessity instead of a toy.  

the Tire and the Brake, 1915 Michelin stopping distances