When we recommend leaving Santo Domingo
We recommend leaving Santo Domingo 4.5 hours before your flight out of STI. This is a genuine cross-country run up the Autopista Duarte, passing La Vega, and while the highway is fast in normal conditions, Santo Domingo's own city traffic getting out to the highway and occasional weekend congestion around La Vega can add real time. STI clears quickly once you arrive, so nearly all of this buffer is the drive itself plus a sensible safety margin, not the airport process. If you are starting from Zona Colonial at rush hour, or connecting from an SDQ flight with a tight layover, we recommend the full 4.5 hours or more.