Yes, they are extra wide sidewalks, but width does not confirm anything about access rights.  Just because shared paths are often wide does not mean that all wide paths are designated for shared access.  For that, we need some signage or official documentation.  

In this case, the simpler explanation for the wide sidewalks is that they are boulevard sidewalks. Many of the city's boulevards have extra-wide sidewalks (Armour, Karnes, Cleaver, Benton, Linwood).  

