I can explain why this happens! In Springfield, new sidewalks are built by the developer at the time of a property’s development (with some exceptions). That hasn’t been the rule forever though, so large parts of the city were developed without any pedestrian infrastructure at all. Now that some of those properties are redeveloping, those without sidewalk are usually required to build it. If it’s a corridor without sidewalk that the City has determined needs the infrastructure, that could mean building a sidewalk with no connection at your property line. This can lead to a patchwork of infrastructure if certain properties do not redevelop when their neighbors do.

The City has a pool of money funded by properties that request to pay a fee in-lieu-of sidewalk, which a special board considers and approves based on the need, etc. in that area. The developer pays for each foot of sidewalk they request not to construct, and that money is then used to build sidewalk elsewhere in that property’s Council district (1 through 4).