An easy solution would be to create a custom delivery option allowing customers to choose “local delivery” if they are within the .25 miles from the store.
Under the shipping options > flat rate > change the name to something along the lines of “Local Delivery (Within 1/4 mile from store location only).
This would be an easy quick fix without having to do any large file modifications.
In regards to involving Google maps and API, this would involve hard coding. if you don’t know programming yourself, I’d recommend hiring a programmer to do it for you.
I currently get between 2-3 requests for modules a day, in which I am currently creating a request form on my website to better handle these module requests. Feel free to PM me for the link.
(Magento team: this is not a spam of service. We support and back Magento. Realizing that the Magento team cannot handle all requests, we are assisting in creating a better Magento environment for everyone by helping in the FREE creation of these modules.)