While most of Maryland and Delaware enjoy relatively low crime rates, Baltimore has a nagging problem with property and violent crime, and Wilmington also has neighborhoods where visitors are advised not to go. The major tourist areas of both cities are fairly well policed, but be alert and follow common-sense precautions.
If you're using public transport, it's best to travel during the day and to keep valuables out of sight. It is safer and smarter to drive or take a cab between neighborhoods (unless otherwise noted) than to walk, even when the distance is not too great. Keep a good city map at hand to help you out if you're lost. Neighborhoods can go from safe to scary in a matter of a few blocks. It's best to keep on the main routes and turn around if anything looks worrisome.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.