Google's support for custom maps has been inconsistent over the past few years, but the My Maps function seems to have finally found a stable home. It's now part of Google Drive, where maps can be created, edited, sorted, and shared like other documents.
The My Maps integration was announced yesterday, and some of the underlying functions aren't new. However, the whole system now works pretty well in a web browser. Users can drop pins, draw routes, measure distances, and add directions across multiple layers. Styling options abound, including a choice of nine different base maps. And, more intriguingly, data can be imported from uploaded files and Google Spreadsheets.
Older custom maps will be moved to Google Drive "over the next week." Updates for the related mobile apps are hopefully on the way, too. Right now, the Android version of Google Drive wants to open user creations in Chrome instead of Maps, and there doesn't seem to be any way to access custom cartography through the native mapping app.