The site could probably charge extra for better quality results.
Perhaps they could split it into a free version using open street data, and a paid version with actual transit routes and other relevant data (tunnels could be marked as 0% sun coverage if they are able to find a data source for it)
Perhaps they could split it into a free version using open street data, and a paid version with actual transit routes and other relevant data (tunnels could be marked as 0% sun coverage if they are able to find a data source for it)