Three maps I think we need:

Map of Shortcuts

Google Maps is awesome but sometimes it just doesn't know about those cheaty shortcuts that can save precious minutes of time on a walk, run or cycle. Take University campuses - some buildings are really wide... you could walk around, or you could just cut through a building by going in through the front door and out through the back. Same applies for bus and train stations, libraries, etc. A shortcut map could be integrated with Google Maps to highlight where your walking route might be optimised (possibly including a clock to show when buildings are closed). Routes should all have a little safety flag too - you could take a shortcut through a building site but that should at least flag you with an amber warning to show that it might not be the safest. Notes like "shortcut only works if you have a student pass" or "not for the faint-hearted - requires jumping off a loading bay" would be helpful too!

Map of Safe

A year ago I used Google Maps to walk between two places in Newcastle that I didn't know all that well. I tweeted afterwards that Google Maps should have a "scary streets" alert on its walking routes as heading off down steps, off a side street, behind a pub felt like a really questionable route choice! Now I know that this isn't an easy problem to solve but with some kind of rating system, or a tie-in with police crime reports, or a heuristic based on how many people choose not to use a suggested route at certain times of day, it might be one with some easy to implement indicators.

Rachel Coldicutt‏ pointed me in the direction of an episode of The Good Wife where they discuss this exact thing from the side of a restaurant which has been classified as being in an "unsafe" area - thank you Rachel!

Extract from the script of The Good Wife (Season 7, Episode 9):

Our venison pot pie was written up in the Trib.
We were Zagat rated.
Then people just stopped coming.
It's hard not to take it personally when it's your baby.
And why is Chumhum responsible? Their maps program Chummy Maps It's supposed to help users stay safe by giving them directions to avoid the dangerous parts of the city.
Green's safe, yellow's so-so, and red means "stay away." When the filter's on, driving directions avoid the red areas.
The filter is always on by default.
You have to manually turn it off.
So you lost your foot traffic? And this Watch when I toggle the filter on and off.
It doesn't show businesses in the red parts of the map.
When this came out, it was like I didn't exist.
It says this is an unsafe area? Yes, a red zone.
It doesn't feel unsafe.
Yes, except for one thing.
Too many people of color.
Our maps are not racist.
It's run by an algorithm.
And math is not racist.
Chumhum is very proud of its diversity and openness.
And yet their Safe Filter deters people from patronizing businesses in African-American neighborhoods.
Chumhum is not responsible for the actions of those who respond to its software.
It was Ms.
Feldman's choice to open a four-star restaurant in a marginal neighborhood, not ours.
It isn't a marginal neighborhood, It's a black neighborhood.

I don't have a solution to this complex issue but it's totally a mapset that would be useful in helping people making good choices about their personal safety.

Map of Shops

I realised recently as I reminisced about the old cafe in the James Thin bookshop on George Street in Edinburgh that any record of the shop (or the cafe) are almost gone (from the internet)... and the same applies to almost every other property around the world. It would be amazing to have some kind of wiki/map combo where people add info about shop names, staff, memorable events, etc. to a searchable, timeline-able map. It would be a confusing jumble in some places, but just starting to collect the info would be an amazing thing.