Saying hello to strangers is regulated to some degree by cultural customs. Some cultures have hard and fast rules about when and how you greet a stranger. Here we have different customs depending on what part of North America we live in. It also depends on whether you live in a large urban area or smaller cities and rural areas. The location and situation you are in also dictates whether you greet strangers.
In larger cities people stare ahead and try to get where they're going as fast as possible. They behave as if you weren't on the street. In some areas safety is an issue. We don't know if someone will take offense to our greeting. Some people seem want to be protected in their own space.
When I ride my bike on the trails I say hello to everybody I meet. Most people return my greeting. The odd one ignores my greeting. When I'm in the mall or a large store I don't greet anybody. Today I took nine birders on a 5 km (3 mi) trail. There were many other walkers. All of us greeted one another and quite a few conversations took place. It was pleasant to talk to strangers. Some were interested in what we were doing.
Now I happen to think there is value in greeting one another. It affirms our existence. It must be difficult to go about your daily business and be ignored by people. We have to have some confidence to greet strangers. It's a pleasure to get a positive response.
My father loved to talk to strangers. He had many stories to tell about the interesting people he met. Being a farmer in the country he talked to anybody who was around.
I had a strange encounter that I'll not forget for a long time. A young fellow was sitting on a bench beside the trail staring out across the small valley. I stopped because I wondered what he was looking at. I greeted him but got no reaction whatsoever. I waited. I started to wonder about the wisdom of talking to this guy. Finally he replied. I responded and it was a long time before I got a reply. I was about ready to get out of there when he offered a comment that wasn't a response. He told me that he had lived in the area as a child and knew the area well as he'd played in these woods.
So there is some risk in approaching people.
So what do you do? Do you greet strangers? Do you talk to strangers?