Opps, sorry about response to your original post. Have a head cold and somehow thought you were talking about cycling (saw you mention bicycle); just realized you are talking about running.
Your closest option would be the streets on Arlington Ridge (to the west of Pentagon city and east of I-395). There are steep grades, about 0.1-0.2 miles long, but ~8-9% (e.g. 23rd Street), or a longer grade more gradual grade 0.5 miles at 5% (South Arlington Ridge Road).
The other nearby hill would be south of Four Mile Run. Either Cameron Mills Road and Martha Custis. Both about similar slope and duration to South Arlington Ridge Road. I should note that there are some gang activity in this area, despite the fact that even a starter home costs quite a bit. So run when it's well lit, etc.
All of these either have sidewalks or have very low car traffic
If you need longer hills, you have the following, not sure about sidewalk conditions, but you can use google maps to check:
https://www.strava.com/...6533?filter=overall; in DC, some parts doesn't have sidewalks
https://www.strava.com/...7170?filter=overall; in McLean, sidewalked
https://www.strava.com/...1228?filter=overall; also in McLean, sidewalked