The early 1900s  featured the gas- powered Ford Model T Field Ambulance which  was able to transport several patients at a top speed of 45 mph. Ambulances  were common place in cities with funding from hospitals retrieving  patients in the field. The Red Cross  utilized these ambulances during  World War I. Many of these remained inservice through the 30’s and 40’s.

Shameless self-promotion alert:
If you go to my online shop, I’m selling postcards and posters featuring this old ambulance as part of a series.