So far (knock on wood) when I have been chased they haven't come so close. I have squirted them with the water bottle and have had moments where I only had to yell. I had one little dog chase me and my step-mom and niece yesterday and as I came up on him, I just yelled "BAD DOG" and he looked at me like I was crazy. LOL
I can usually tell when they are just chasing you because you are moving and when they are being really aggressive, and the little dogs that are just chasing because your moving, always scare me that they are going to come into the road and get hit.
I would hate so much to witness someone's family dog getting hit by a car. I know I would just be a mess if I did.