Roseau itself is small enough to walk in 20 minutes end to end. For excursions, the cheapest option is the shared minibus system — flat-fare minivans with red H-plates that depart from set stops along King George V and Independence Streets. Routes are colour-coded; the conductor will call out the destination. Service is frequent until late afternoon and tapers off after 6 pm.
Taxis are plentiful but unmetered: agree the fare before getting in. For multi-stop tours of the island's waterfalls and parks, hire a driver-guide for the day — most hotels and guesthouses can arrange one. Self-drive is straightforward (rentals are easy to come by) but the mountain roads are narrow, steep, and demand confidence.