From the you tube video notes:
The origin of the film was an enigma for many decades, and it was long thought to have been shot in September of 1905, after being dated as such by the Library of Congress based on the state of construction of several buildings. However, in 2009 and 2010, film historian David Kiehn, co-founder of Niles Film Museum in Niles, California, dated the film to the spring of 1906 from automobile registrations and weather records. Kiehn eventually found promotional materials from the film's original release and dated the film to April 14th, 1906, and finally gave credit to the filmmakers, the Miles Brothers.
Accuracy: Automobile sounds are all either Ford Model T, or Model A, which came out later, but which have similarly designed engines, and sound quite close to the various cars shown in the film. The horns are slightly inaccurate as mostly bulb horns were used at the time, but were substituted by the far more recognizable electric "oogaa" horns, which came out a couple years later. The streetcar sounds are actual San Francisco streetcars. Doppler effect was used to align the sounds.