Google Maps is a web-based geographical search tool. The purpose of this tool is to allow users to search for a particular location. The service can show a view, similar to a road atlas, of the surrounding streets. It can also provide directions from one location to another.
Several other websites already exist that provide similar services, such as Mapquest and MSN Maps. However Google Maps has some interface refinements that improve the user's ability to find the locations they are looking for. In this critique, I will focus primarily on the map area itself, and will not address other portions of the interface, such as the methods used to input a target address.
The map display has easily readable text, and the color scheme is well-chosen. Major streets are shown in yellow, which is a highly noticeable color for most users. Minor streets are in white, with black borders. This provides good contrast, and requires little effort to discern the paths of the streets. Well-rendered, and antialiased text makes the street names readable.
For comparison, the map below is provided by MSN Maps for the same location. The same information is provided by each, but I find that the Google version is far more readable. MSN Maps uses thin grey lines for minor roads. There is low contrast with the grey background. Major roads are thicker, and use a tan color that provides somewhat better contrast, but is not nearly as not noticeable as yellow.
Generally, a user will use a site like Google Maps by entering an address he or she wants to find. The website will then display a map showing that area. However, it is often necessary for the user to "explore" the area shown by the map. For example, they may want to see an area that is off the edge of the map area being displayed. In Google Maps, if the user clicks on the map area and drags the mouse, the map area scrolls with the mouse movement. This capability is indicated by changing the cursor to 4-way arrows when it is over the map area, which should help the user to discover this capability. In comparable websites, the map area is moved by clicking on the edges of the area. This is similarly easy to learn, but only allows the user to scroll the map area by a fixed amount.
If the user resizes the browser window, Google Maps will expand or shrink the map area, according to the available space. This feature is also useful for the case where the user wants to explore slightly outside the map area.
One problem with the design of the map area is the legend at the bottom, which indicates the scale of the map, and displays some copyright information. This is black lines and text, which are shown on top of the map area. It overlaps confusingly with the black text on the map itself, and as the screenshots above illustrate, makes the road names at the bottom of the map area nearly impossible to read. The scale information on the legend can be difficult to read, which makes this information far less useful than it otherwise would be. The designers should consider moving at least the copyright information off of the map itself. This information never changes and adds no usability to the map area.