Starting today, when obtaining a link to a Google Maps using the ‘Link’ button on the upper right-hand corner of the page, you now have the option of obtaining a convenient, shortened link by clicking on the ‘Short URL’ check box. Shortened URLs can make it easier to coordinate events and share maps with your friends.
We only use g.co to send you to Google web pages, and only Google Maps can generate a g.co/maps URL. This means that you can visit a a g.co/maps shortcut with confidence, and always know you will end up on a Google Maps page.
Source: Google Lat Long