Pedestrian safety on the sidewalks throughout the city.

My wife and I have lived in the city for over 26 years. We love to walk this beautiful city, however improper pruning of the trees (or no pruning at all) have always been an issue. I am 6' and my wife 5'8" tall. We often have to duck or squeeze past trees (some with thorns) planted in the sidewalk or overhanging from adjacent properties. Also, when new trees are planted, they are not trained by pruning to shade the sidewalk without blocking it. Couldn't we have property owners take care of this just like we do for snow removal, trash placement, etc.?