Most unpaved roads here alternate between being extremely muddy and treacherous during the rainy season and being extremely dusty during the dry season. That said, it can be a real adventure exploring the coastline if you have a 4WD or a hired driver with a good, sturdy car. The major artery in this region is the Pan-American Highway (CA 1), which heads northwest from San José to Liberia, then due north to the Nicaraguan border. It's fairly well maintained, but the convoys of trucks and buses often create heavy traffic and there are few passing opportunities. Construction to widen the highway south of Liberia began in 2012, creating sporadic delays. To skip the hours of frustrating driving, consider flying into Liberia, whose airport provides easy access to the region. Local hotels and tour companies can help you arrange for ground transportation in many cases. In Guanacaste, it's usually safe to take pirata (pirate, or unofficial) taxis, but always negotiate the price before getting into the cab, or ask your hotel to call a reputable driver.
The northwest is accessed via the paved two-lane Pan-American Highway (CA 1), which begins at the top of Paseo Colón in San José. Take the Friendship Bridge (aka Río Tempisque Bridge) across the Tempisque River to get to the Pacific beaches south of Liberia. Once you get off the main highway, dust, mud, potholes, and other factors come into play, depending on which beach you visit. The roads to Playa Flamingo, Playa Conchal, Playa Brasilito, Tamarindo, Playa Grande, Playa Sámara, Playas del Coco, Hermosa, and Ocotal are paved all the way; every other destination may require some dirt-road maneuvering.