Local governments in New York generally do have power to reduce speed limits. Most cities and villages have 30 mph throughout the built-up area or even inside city limits, no justification required. (Speed trap on NY 89 entering Ithaca, for example, long before the urbanized area.) They can also post “linear” speed limits, speed limits only applicable to a section of road, and are supposed to justify them with an engineering study. A perennial topic in Albany is extending the same privilege to “towns,” which are a distinct type of municipal government. Cities can post speed limits but towns can’t.