This was published two years before the Ford Model T came out. At a time where Olds, Cadillac, and Buik each made between 1000 and 2000 cars a year.

Chicago had already introduced its city wide license plates, but had won the right to enforce the use of them in front of appellate court just the year prior. Ilinois as a whole only introduced them a year after this comic.

Even in 1909 the Plan of Chicago introduced bigger streets not for the benefit of the automobiles but for the horse drawn cargo carriages going to the railway stations that clogged downtown. They had to make adjustments later because so many Model T's were on the streets by then.

Back in 1906 the streets didn't belong to automobiles yet, streetcars were the thing everyone used all the time, and I don't think laws were specifying right of way yet