In a Zombie Walk, people gather as a flash mob, without any supervision or oversight by town officials, at a predetermined location, and then take a walk together.
The gimmick, however, is that they are all dressed as mindless zombies, and moan, groan, and lurch as they shamble down the street.
Zombie Walks are designed to take the zombies along areas of high density populations, especially where outside dining might occur. A sample path might be from Central Park to Cafe Bernardo, Bistro 33, and then down to the Davis Commons. Zombies do not harass the populace, and are surprisingly peaceful, but sometimes they might encounter people along the way who are eaten and then transformed immediately (via rapid make-up application) into zombies themselves. A number of Zombie Walk videos can easily be found on Youtube.
There is some disagreement amongst zombie aficionados as to the allowed intelligence exhibited by zombies. The Romero school says that zombies must remain essentially vegetable in intelligence. The revisionist O'Bannon school of thought is that zombies are allowed to have somewhat more intelligence, and are prone to groan out the word "braaiinns." Fortunately, these two zombie subspecies seem to coexist peacefully. The so-called "fast zombies" do not participate in Zombie Walks. Presumably they attend Zombie Runs.
In 2007, apparently a bicycle version of a Zombie Walk occurred in Davis, which was called Zombies Reclaim the Streets. Otherwise, Davis seems ripe for its first Zombie Walk. A clearinghouse for Zombie Walk information can be perused at Zombiewalk.com, where the last area Zombie Walk reportedly occurred in Sacramento in 2007, in Old Town.
Campus intersections, especially near the beginning of the school year, may appear to have many of the attributes of a Zombie Walk, but do not quite qualify.
In the case of a real zombie emergency, the Davis Zombie Attack Response Guide could be of considerable assistance.