Conclusion: take the MRT for short hops, rush hour and avoiding traffic; use Grab when you have luggage, travel late, or go cross-district. • MRT Jakarta: driverless with contactless payment (e-money/QR); trains run on time regardless of traffic and fares are cheap — great for budget travellers along the main corridor (e.g. Bundaran HI). • Grab: app-based, no fare negotiation, door-to-door; best with luggage, off-station destinations or at night. GrabBike can weave through jams but ride with caution. • Tip: reach central sights (Monas, Kota Tua) by MRT, then use Grab for the last mile to balance cost and convenience.