It's easy to get a taxi, but expensive. You could take the $5 shuttle bus to the Silver Line Metro station (subway), and get a taxi or Uber (or walk) at the other end. Metro costs up to $6 and can take about an hour.
DC is pretty spread out but my guess it would cost you $50+ You could also cab it to the metro in Reston and spend 45 minutes on the train. Depending on traffic this could be just as fast. There is also a metro bus connection at the airport (less than $10).
Yes, but rates depend on many factors. I support Mr Cujo (thanks Cijo for your right guidance)
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