is a car a practical alternative to train to travel from bejing to changchun china for an american for about 1

i mean a rental car

No! Driving in China is totally different from driving in the US! The road condition is different, and if you don't read Chinese, that is another problem. Traffic regulation and the way local people drive are all different...

I will highly recommend the train: take the express train Z61 from Beijing to Changchun (22:40 - 7:00), only sleep over night for 8 hours, you will wake up in Changchun. The price is only 365 Yuan ( about US$45) for the soft sleeper. You will be totally hassle-free!

It is not practical, the train is your best option. In addition, your american drivers licence will not be valid to drive there. Even the validity of the international drivers licence is not recognized by the Chinese government.You cannot drive with an International Driver's Permit in mainland China; China has not signed the convention which created IDPs. You need a Chinese license to drive in China.

For foreign residents but not tourists, China laws say that foreign residents can obtain a driver's licences and that an IDP can be converted to a local licence, possibly with an additional examination. But in practice, getting a license may be complicated and the requirements will vary from region to region and over time. Some foreigners are asked to take a written test in Chinese. Others get a bilingual test forms, or are allowed to bring a translator. Sometimes you can be excused the actual driving test if you have a foreign license, sometimes not.

In response to your question and answers below, here are some realities about driving in China:
1) I do have a Chinese driving license. As expat / resident you are allowed to take a test and get a license. The test is only a written one and is in English! 100 questions -- you need to get about 75% right to pass it. FESCO in Beijing will help you schedule and organize for the test. The cost is 800RMB. The license is good for 6 years.

2) You will need to show your US drivers license, passport with resident visa, photos, and the fee

3) Renting a car in Beijing is not that difficult but rent costs are very high. A Buick van will run you about US$1500-1700 (with driver and insurance) per month with a one year contract.

4) Now, about driving to ChongQing -- it is not that great of an idea. The roads in China are still not well connected. You might be able to travel from point A to B on a very good highway, but then B to C might not be connected with a highway but a rural road, then C to D might have highway again. Tough to predict....

So all in all you would be better off to fly to ChongQing and then rent a taxi for a whole day while there. I have done that in many places in China (Chengdu, Shanghai.....). A taxi for the day could be around RMB500-RMB600 (with the driver) based on the city.

It would be very hard to drive in China. Most signs are in Chinese character. So, unless you understand them, go ahead...