talking about dogs

The act you mentioned by the dogs , especially the stray ones is their reaction towards their enemy in general . It's usually a reaction towards their predators arousing due to fear. The bark of a dog is just like the Snake's Hiss towards a Stick carried by snake charmer . They tend to think that they are about to be attacked and hence creates a warning sound towards their enemy (In our case the Cars and Bikes) . Once they are confident that they are safe from any danger , they stop barking and return back to routine . what would you do if a Speeding bike or car whizzes past just inches from you..our reaction would either be to avoid it and if we cannot we either shout or cry from fear... It's just the same reaction from dogs...

It's a dog's instinct to chase anything that moves and to protect their territory; even stray dogs will stake out an area and consider it theirs to protect. When the intruding car or bike is beyond what they consider their "property line" then they give up the chase because they've achieved their goal of getting rid of the intruder.

There should a an authority to take care of the stray dogs because if ever they attack someone on the road it can cause a serious problem or if ever they are hurt they can have bacterias too, it is better to call the department concerned to take care of them.