6 things to know about Rochester's speed limit change Reduction to 25 mph on Rochester's residential streets won't start until new signs are put up in the spring. 6:00 am, Dec. 28, 2020 × A speed-limit sign alerts drivers on Tuesday, August 18, 2020, along 11th Avenue Northeast in Rochester. While some signs will need to be changed, Rochester's plan to reduce limits on residential streets calls for paying for the effort out of the existing Public Works operating budget. (Traci Westcott / twestcott@postbulletin.com) The authorization to set 25 mph speed limits on Rochester’s residential streets isn’t fueling immediate changes. Here are a few things to know about the planned changes: