Short dive into history
Drawing on the streets began in Italy in the XXVl century and is a long tradition in cities of Western Europe. Artists, traveling with Catholic religious and folk festivals, using chalk, painted Madonna images on the streets. These artists became known as 'Madonnari' or street painters.
Street artists existed (and, I suspect, exist, but have not yet found information about it) from passers-by coins cast on their paintings as an evaluation of the work: work and talent.
The most famous festival takes place in the tiny town of Grazie di Curtatone, in Italy, where every year in August (since 1972) artists compete on the square in front of the huge cathedral, painting for twenty-four hours. I saw photos of several similar festivals on the Internet (the most famous is here - I Madonnari Festival).
In 1987, Katie Kouri, executive director of the Children's Creative Project, created the festival “I Madonnari” as a fundraising event to improve the quality of arts education programs in Santa Barbara County.