google mapsgoogle-my-maps
Background:
I am looking into the ways of inviting people to add markers to a map that I created using My Maps of Google Maps. I know that I can share the link to the map with editing rights but ideally I would want people to fill in a form to provide all details which are then automatically added to the map on form submission.
Is this possible with Google Maps?
Per this Google Calendar help link there is at least a way to link a map location to an event, though it is not exactly what you want to do, it's close.
When you fill in the "Where" field on the "Create Event" page, Google Calendar will create a link to a Google Map search result. To ensure an accurate result, please enter a full address, including city and state.
Note: The "map" link won't appear until you save the event.
I tested this and it works -- you must enter a mappable address in the location field, then after you save the map, a map link will appear on the event:
You need to cluster your markers. It's tedious to do on the server side, but there are a few client-side clustering plugins you can use. The most popular one is MarkerClusterer.
MarkerClusterer v3:
Why many markers degrade performance, and how to improve it (MarkerClusterer comes out tops):
Best Answer
I have not heard of Maps offering Forms like that.
You could build a solution using a Google Form, and a script that edits the map when the form is submitted.