Is Hop-On Hop-Off Bus (Big Bus / Old Town Trolley) worth it solo?
DependsSolo
Solo, it depends on the day.
Genuinely useful precisely because DC's sights spread over a long, hot Mall: Big Bus Tours runs an open-top Red Loop past the Mall and White House (~17 stops), while Old Town Trolley runs a single live-guided loop (~15 stops) with Georgetown and Arlington shuttles. Either spares the legs and adds narration, which matters most for multigen groups. The honest catch: DC traffic and frequent stops make them slow, and for able-bodied visitors the Metro plus the $1 DC Circulator Mall loop is far cheaper and often faster.