Discovering
Overlays and
Mash-ups
T
wo common techniques for increasing functionality in Google Maps
applications are overlays and mash-ups. In an overlay, information is
placed on top of a “hot” map, which is an interactive and controllable
map of a particular area. For instance, you can layer restaurant location data
on top of a Google street map. In a mash-up, a variety of information is
combined to create an entire application. For example, you can overlay tran-
sit maps onto a Google street map and then provide additional information
and functionality, such as route guides.
This chapter presents some excellent examples of existing applications that
use overlays and/or mash-ups to enhance the usefulness of a particular web
site. Not only are these web sites convenient, practical, and fun to navigate,
but you can also use them as inspiration when you begin to create your own
applications.
Traffic Solutions
For maps that include road data, providing interactive information on the
traffic situation or better ways of finding your way around are excellent ways
to extend the utility of the map beyond a basic overview of the surrounding
environment.
Toronto Transit Commission (TTC) Map
Toronto has an excellent public transit system, but some elements of the
underground system are less than clear. There are, of course, plenty of maps
and guides to how to get around, but they are not always easy to use. For
starters, working out the precise location of the station compared to the
street on which it is located is difficult. The maps of the subway are either
named explicitly or stylized to the point that street names are not a critical
part of the identification. Even if you are looking at a combined street map
and transit map, the detail may be so small that what you are looking for is
difficult to identify.
̨Toronto Transit
Commission
̨U.K. speed cameras
̨Hurricane maps
̨International Space
Station and Hubble
Telescope Tracker
̨Remaining Blackbird
Spotter
chapter
in this chapter