Its more of a stopover than a layover. I decided to have an overnight stay instead of a 5hr layover at IAD. Will be staying at either downtown or near Dupont Circle.

Arriving at 3.30pm and departing 2.30pm the next day. It appears that traffic is going to be heavy going into town at 4-5pm. Does it still make sense to take a taxi into town or will the fare end up to over $100 with the traffic ?

Also, how much should I offer the cab driver for a 15-20 min wait at the Jefferson Memorial, $5-6 ? (I had a short stay in DC before but never used the cab, hence unfamiliar with the cab "etiquette")