The are 6 different ways across 3 unique modes of transportation to help you travel from APG to Baltimore. If you're only considering the price, you should check out the train out of ABE towards BAL, as it is the cheapest to Baltimore. It's common to find tickets for as low as $6. Amtrak operates from APG to Baltimore, so you book your trip with them! Take the train, it is cheaper and more comfortable than the bus!
The trip to Baltimore is an excellent trip for the day or a nice trip for the weekend from APG. The cheapest way to get from APG to Baltimore is $6 and the quickest way takes just 32 minutes with the train.
While buses have recently gotten bad coverage because of cleanliness of bus stations or winter time accidents, they are can be very convenient for travel. The best part about traveling by bus to Baltimore is that it can be very cheap. That's because they usually have basic accomodations - WiFi and a restroom. Some of the APG/Baltimore buses' coverage has been overstated. The real thing to consider when taking a bus from APG is to consider the time of travel and the density of the cities that you're traveling to. If you are traveling by bus between APG and Baltimore during high traffic times, you can expect to have your trip altered significantly due to traffic. Further, if you are traveling during winter, the bus schedule might be thrown off due to inclimate winter weather. Be sure to plan accordingly!
The plus side of taking the train from APG to Baltimore? The accomodations, scenery, and lack of Baltimore traffic can usually be on point. Moreover, you can usually expect your average concessions - such as food and drinks. Most trains have WiFi these days as well. The worst part about trains are the price. While the train to Baltimore is often cheaper than flying, they are generally more expensive than buses. Train prices are usually set and do not vary as much as bus prices or flights or so the likelihood of finding discounts is pretty rare.