Im not 100% sure but I think when the game returns from visiting a web page there are 2 ways to control what is displayed.
1. One way is to show a plaque (or other ARIS object) when the page 'has been seen' using a trigger. Furthermore in a plaque you could use ARISjs to redirect directly to a tab like the map when the page has been seen.
2. Another way I think is to take advantage of the fact that when ARIS does not have a specific thing to show when you come back from a web page, it will show the tab that is on the top of the tab list as a default. So if you moved the Map tab to the top of the tab list, the map would become the default thing that ARIS would show when it has nothing better to do.