Modern traffic laws in the United States originated with a New York businessman named William P. Eno (1858-1945), who has since been dubbed "the Father of Traffic Safety." At the turn of the century, New York City was facing unprecedented levels of congestion; mainly from horse-drawn carts and electric trams, as the automobile was still in its infancy (although the extant gasoline automobiles were responsible for more than their share of meyhem). Responding to the issue, in 1900 Eno wrote "Reform in our Street Traffic Urgently Needed," published in Rider and Driver Magazine. which laid out basic recommendations like positioning "stop signs" at intersections. By 1903, Eno had developed a comprehensive traffic code for the city of New York, the first of its kind anywhere in the world. Later inventions of his include the pedestrian crosswalk, the one-way street, and the rotary. Interestingly enough, Eno never actually learned to operate an automobile himself; he was always driven around by his chauffeur.

As for the second half of your question about how it became "standardized," that's somewhat outside my historical purview. However, I'm not so sure that it is standardized - driving in foreign countries (even those that share a common language) can be very disconcerting. Perhaps you could elaborate on what you mean by "standardized internationally?"