Washington, DC’s Metro system covers the National Mall, downtown, and most major sights, making a rental car unnecessary for a typical monuments-and-museums visit.
Metro and Walking Cover the Core
The Mall’s Smithsonian museums and major monuments are walkable to each other, and Metro reaches Georgetown-adjacent stops, Capitol Hill, and Reagan National Airport directly.
When a Car Helps
Mount Vernon, parts of Northern Virginia, and day trips toward Shenandoah National Park are all easier with a car. If you flew into Dulles or BWI rather than Reagan National, a rental (or at least a rideshare budget) is worth planning for since neither connects to Metro as directly.
DC Traffic and Parking
Downtown DC traffic and parking are both genuinely difficult, and many streets have restrictive permit parking. If you rent, budget for garage parking rather than counting on street spaces near the Mall.
Compare rental rates above if Mount Vernon or Virginia day trips are part of your plans, or check flight and hotel options if you’re keeping things downtown.