From google map version 5.7,this is going to be a matter of past.With the introduction of "download map area" google answered the request of many end-users.
From their post,
When you’re visiting an unfamiliar location, Google Maps for mobile is great for getting an idea of how close you are to your destination, where streets and landmarks are in relation to each other, or just for getting “un-lost.” But what if you don’t have a data signal, or you’re abroad and don’t have a data plan? We say that if you use Google Maps for mobile, you’ll never need to carry a paper map again. The “Download map area” lab in Google Maps 5.7 for Android is a step in making that statement true even when you’re offline.For now,no satellite view and 3D buildings, search for Places and get directions support will be available to offline users though.
Let’s say later you’re visiting Bordeaux during a trip to France. If you were to open Google Maps for mobile and zoom into Bordeaux without data coverage or wifi, you’d see the image on the left:
Left: Bordeaux with no data or wifi. Right: Bordeaux with downloaded map area
That’s not particularly useful when you’re trying to find out how close you are to the Cathedrale St. Andre. But a little advance planning and “Download map area” can help. Before you take your trip, while you still have access to WiFi or data coverage, you can open up any Places page in the world, click “More” to get the Place page menu, and download Google’s maps for a 10-mile radius.
Left: Tap a landmark to enter its Place page. Right: Place page “more options” menu