You can always ask nicely from a reasonable distance (at absolute minimum 15 feet... as in, 2 x 6 ft leashes plus a gap) but really, I would not suggest you wanting your dog to greet strange dogs on the street.
If you want to socialize, sign up for training classes like a CGC class and socialize there plus meet some more dog owners to set up your own walks or play dates. A well run dog daycare is another option.
I have one dog friendly dog (Chester) who knows how to greet properly with a butt sniffing. But I still won't let him greet strange dogs on walks because all too often, the other owner has no clue. For example, one walk back when, we met a girl and her medium sized dog who seemed friendly and she said he was friendly and I let Chester greet the dog. Who then spun around and leapt on Chester while snarling and snapping. I pulled Chester away and shouted "What the heck!?" to the girl. She said, "Oh, he does that sometimes...." WHAT?
It also protect Chester (and me) from owners who might get bent out of shape over something like a scratch from two dogs playing or those who don't understand that dogs can play rough and might freak out that they were fighting.
Practical considerations like simply getting leashes tangled is also an issue; when my friends bring dogs over or we meet known dogs at the park, we just walk, no playing, and they are only allowed to play off-leash in my yard.
My current foster dog is not dog aggressive but she is overexcited by dogs and does not yet know how to greet them correctly. So she is a "DINOS"- Dog In Need Of Space- and when we go on group walks, she will wear orange to notify people to get her extra room (from other dogs, people are A-OK). Several of the rescue groups and trainers here in town have agreed on and are promoting the use of orange for DINOS. If a dog approached her in a strong/aggressive manner, she would react aggressively/defensively, so as a preemptive move, I ask people on trails etc politely to give us passing room or I cross the street early if possible. Because I am crossing the street well before she can react to another dog and she walks so nicely on the leash, and she really does want to play with the dog so it makes other owners think she might be a good candidate to greet. Which she is not.