OK from another article I found that there was another 7-11 closer at 1125 Rinehart Road, Sanford, FL
The distance from the dispatched site at 1111 Retreat View Circle to 1125 Rinehart shows to be 0.78 miles
Round trip of about 1.5 miles. Much more credible.
I had also heard a commentator on the radio say that Zimmerman had observed Martin walking close to the buildings. She speculated that he may have been trying to avoid the rain.