• If someone intends to scroll down a page using the mouse wheel and the map size is large, there is a high probability that the mouse pointer will be over the map and the map will zoom instead of the page scrolling. The map zoom change is typically huge, the user doesn’t see the intended map view and they are lost or confused by a large number of map markers where they should be seeing one or very few.
• Even with a small map size, if the mouse pointer happens to be over the map, the map will change instead of the page scrolling. The change is typically huge, the user doesn’t see what was intended to be shown and they can be lost or confused.
• In applications spanning large geographical areas there can be multiple clusters of closely-spaced map markers, for example, where there are many closely-spaced locations within each of several widely-spaced cities. In such applications, a user who zooms and/or moves the map can become lost and not know how to restore the original view.

Any of those problems can be fixed by reloading the webpage, but some users don’t realize that. Even where they do, reloading the page can take significantly more time than repainting the map would, depending on other page content, server workload, internet bandwidth, and other factors. How much trouble would it be to add a small “Reset Map” text link centered above each map?