One thing that some folks can’t comprehend or get through their skulls is....a Neighborhood Watch job is different for different types of neighborhoods. My ex was temporarily our ‘watchperson’ in our neighborhood years back in Houston. But all he did was patrol up and down the streets in his truck, looking for suspicious activity.
IOW, in a non-gated neighborhood, the watchperson could and should stay in their truck/auto most, if not all, of the time...since that is the only thing they can do is drive up and down the streets.
In a gated condo community, however, the job is or can be much more pro-active as far as the necessity of getting out of your vehicle and observing in and around the housing units. Zimmerman was just doing the job thoroughly. Who knew he would encounter a teenage thug with a chip on his shoulder and already a record of getting into trouble and drugs.
Our neighborhood watches around here are ALL on foot.