Here where I live, properties facing busy streets have wide easements (Sometimes thirty feet or more..) which are usually landscaped with trees and heavy shrubbery (Oleander is a favorite here)
Hazards of the type you describe are actually more likely to present themselves from the inside of the sidewalk, where it is very easy for a sketchy person to hide in the shadows. But, again whatever the couple is comfortable with and makes them happy.
To give you an idea of how antiquated early editions of Emily Post have become, consider what she says in the same chapter about bundles:
"Bundles do not suggest a lady in the first place, and as for gentlemen and bundles!—they don’t go together at all....And yet, many an unknowing woman, sometimes a very young and pretty one, too, has asked a relative, a neighbor, or an admirer, to carry something suggestive of a pillow, done up in crinkled paper and odd lengths of joined string. Then she wonders afterwards in unenlightened surprise why her cousin, or her neighbor, or her admirer, who is one of the smartest men in town, never comes to see her any more!"
The harkens back to a time when carrying a woman's larger shopping purchases was the job of house servant. Fine ladies normally didn't do it and gentlemen certainly did not.
I think the bottom line is that there is a huge difference between what you might volutarily choose to do and what a total stranger would expect of you as social norm.
To give an extreme example: You might choose to step in front of a bullet if it would save the life of your wife or child, but does a total stranger have the right to expect that of you based on nothing but your gender?