Have a couple of friendly one-liners you use every time and pair them with keep-it-moving body language. Examples that work well are, "So good to see you. I can't stop right now and heading to work," or "I only have a minute while I walk to the car." Keep your feet pointed in the direction you're going, keep walking, hand on the door or keys visible, and smile as you say it. Another good one is, "Walk with me for a minute?" If they join you, you can end with, "I've got to peel off here.
Catch you later." You can also time box politely at the start with, "I've got two minutes, then I need to start dinner," and then actually end it when the two minutes are up. Earbuds in and a quick wave can also signal "not a good time" without words when you are really rushed. The key is warmth in tone plus a clear exit cue every time. If it feels right, do a one-time reset on a neutral day: "Hey, I realize I often look rushed. Weekday mornings and when I get home I try not to stop, so if I seem brief I'm not being rude." Offer an alternative to keep things friendly, like, "I'm more chatty on Saturdays," or "Happy to catch up when I'm grabbing mail in the evening." Consistency matters, so use the same phrases so it does not feel personal or variable. If they keep rolling past your boundary, repeat and close the loop: "I do want to chat, but I need to go now. Talk later." Most neighbors read the pattern quickly when you mix kindness with a clear, predictable exit.