I commute from west to east on the W&OD into Tysons. If you are willing to possibly lengthen your commute a little, then I would continue west on the path past Gallows, through Vienna, and get off on Clarks Crossing. From there, you can continue into Tysons through mostly neigborhood streets, which are much safer and less traveled than Gallows Rd. It is a less direct route obviously coming from Arlington, but you can minimize your time in the Tysons traffic. Whether this would make sense depends on what part of Tysons you will be working. If you are near the Mall or Galleria, this route would take you in through the "back door" into Tysons and you would only be in true Tysons traffic for about 1.5 to 2.0 miles. And depending on the time of morning/evening, part of that 2 mile stretch could have light traffic and you would not see the worst of it. Even at its worst, this stretch is not as bad as Gallows. In all, this alternate route would add about 6 miles to your commute each way.