I have already created this feature but manage it manually via "My Maps" by Google Maps. See here: amandavernon.com/tour. This could be done using Google Maps but needs to be synced with BIT somehow so that events are added when published and removed when completed automatically. Reverbnation used to do this with BIT data sync but they got rid of it I believe, or switched to only show events that were in the next week. I wanted ALL upcoming events shown. It's impressive to see and allows fans to find your nearby gigs visually.
Note: See in the second image attached...it's important that when a fan clicks an event plot on map, it at least gives the venue name and a link to the event on bandsintown for full details.