You can take The Maglev High-Speed Train right from Shanghai Airport. I'd suggest a minimum of a five hour layover if you are going to visit "The Bund" waterfront area. Chinese immigration can be fickle. I watched many travelers not allowed into Shanghai because they had a layover of 12-hours or less. I was lucky to have an overnight layover so I breezed through. Four weeks later I was allowed to enter China for my 10-hour layover? It appeared the rule had changed quickly but I was still given a hard time for not having a written itinerary, so, I'd suggest having a written plan of action as a precaution.
The Maglev train is more expensive to ride than the standard train but is one of my favorite ways to travel for three reasons:
1. It saves time.
2. It travels at speeds up to 430 KM/H or 267 MPH.
3. The seats are wide and it is uncrowded.
It is pretty amazing to have such a smooth and comfortable ride while moving at over 200 miles per hour. I took the Maglev Train from Pudong Airport (Shanghai) to The Longyang Station. You then hop on LINE 2 and ride for about 20 minutes to East Nanjing Station to get to the shopping area where it is an easy walk to "The Bund".
You can save money and take the standard train ("Line 2") from the airport but I'd recommend splurging on The Maglev high speed rail (at least once) and save 20-30 minutes.
The Maglev + "Line 2" journey takes about 40 minutes to reach "The Bund" where you can enjoy a walk along The Huangpu river which divides the two regions of Shanghai: Pudong and Puxi. You can cross the river by bridge, underwater tunnel or the ferry.
My favorite is the ferry. It is inexpensive and you enjoy the fresh air and and views from the water...
Until you reach The Oriental Pearl Radio & Television Tower !