From the Daily News:
Q. I'm undocumented. Can I travel within the United States by plane, train or bus? My husband and my three children are all U.S. citizens, but I've never managed to get legal status. I'm not sure that I'll ever get it.
Narda Robinson, Bronx
A. Many undocumented immigrants travel freely throughout the U.S. without encountering immigration officials.
It is unlikely that traveling by car, bus or train will be a problem unless you visit an area near a land border. For instance, if you were to visit Niagara Falls, N.Y., near the Canadian border, your risk of getting caught increases. As for air travel, some experts don't recommend it, but many of my undocumented clients have flown within the U.S. To board an airplane, all travelers need an ID issued by the government. A foreign passport meets that requirement. Of course, if an incident occurred on the plane and the authorities carefully interviewed all passengers, you could face problems. For information on documents that qualify you to travel by air, go to the U.S. Transportation and Safety Administration (TSA) Web site at www.tsa.gov. Click on "For Travelers," then "Acceptable Identification at the Checkpoint."
Don't forget to pick up the official NYC Guide, "Welcome to Our Sanctuary City" translated into 15 languages for your convenience.