My dog growls and lunges at other dogs while walking with their owners?

I rescued a male Rottweiler several months ago and read multiple books including Cesar Milan's book. I haven't been able to figure out how to get him to walk by other dogs and their owners while we are taking our walk. We walk about 2 miles in the morning and another 1 mile in the evening. I take my neighbor's dog with me. He follows other commands, sits for extended periods of time while I clean up after him.