Here's the metro trip planner web site. Good luck with your interview!

http://www.wmata.com/rider_tools/tripplanner/tripplanner_form_solo.cfm

$49 is a great fare for Amtrak. The train is WAY more comfortable than the bus. Even for people not 6 feet. I know that Bolt (and the others) all advertise leg room -- IMO it's not nearly as comfy as they promote, plus they are often full so the arm room can be limited if you are next to a large person. They all advertise free wifi, but I've never been on a bus with wifi. And only one with movies.

Don't get me started on the bathrooms...
Granted, I've only been on 3 (DC2NY, Bolt, and one other. But I've learned my lesson. I will ALWAYS take the train over the bus.

You've allowed more than enough time to get to Ballston. Good luck with the interview.

Just to clarify--If you are going to a location at the intersection of N. Randolph Street and Fairfax Drive in Arlington, then the closest Metro station will be the Ballston Metro station.

Be aware that Metro does extensive repair/maintenance work on weekends so it closes some stations and track segments; there is reliable bus shuttle service for affected locations, but everything takes 10-30 minutes longer. Check the Metro website and the Washington Post on the day before your Saturday travel to see if your route will be affected. The weekend work is halted for a few weeks in late March-early April because of the increased passenger demand around the festivities/holidays, so you would not be affected at all if your travel is during that time.

I agree with the train over the bus. The legroom on the bus is minimal (based on Boltbus). It would depend on how much you are saving but I would take the train over the bus anyday.

Instead of riding the train to Union Station, you can get off at the New Carrolton station and transfer there to the Metro Orange Line. If you ride to Union Station, you need to take the Red Line to Metro Center and then transfer to the Orange Line. No real time savings, but you cut out a transfer.
As kayd noted, make sure you check the track work announcements in advance.

Thanks everyone for all of your great suggestions,the metro website link, and well wishes for the interview. You guys are great! This is my first time on Fodor and using a forum of any kind.

I would agree that that the train is better than the bus; but, I just finished graduate school, my funds are limited, and I have to continue to make some sacrificies, i.e. comfort, to save some money. I have never taken any of these bus lines, so I am trying to pick the lessor of the evils, so to speak. Again, I heard none of them are consistently good-lateness, unorganized, rudeness, offensive odors and people. And I don't want to even think about the bathroom situation-YUCK! The difference is about a $30-35 dollar savings. I know its not a big amount, but every penny counts for me.

I have some other out of town interviews coming up if I get to the next step so I need to save money. Chicago maybe on the radar next trip which will be a plane ride plus hotel overnight which will not be cheap.

I have given myself 1 1/2 hours to get there. Hopefully, even with construction and delays, I will more than enough time. As Kayd & Kja suggested, I will check the internet-Washington Post and Metro website-the day/night before I travel for advisories. NYC is the same way on the weekends with construction delays. I'll bring a good book.

Ok, so based on your feedback, once at Union Station, I should take the Red line to Metro Center, then change to the Orange Line to the Ballston Stop and I should be near walking distance to Randolph & Fairfax. On my return trip, I should take the same lines back getting off on the same stops. Is that correct?

And while not the preferred mode of transportation, Boltbus is OK? Or should I take Megabus or DC2 NY or TRIpper?

Yes, Red Line to Metro Center. Orange Line from Metro Center to Ballston station. Ballston station is located at Fairfax Drive and North Stuart Street. You just need to walk two blocks east to be at Fairfax Drive and North Randolph Street.

Do everything in reverse to return to Union Station.