There are several choices for use of public transportation in Santo Domingo, though some are better than others. The public buses, though least costly, are usually crowded and hot and make many so many stops that much time can be wasted.

Taxis can be expensive, cramped and unsafe, especially for women traveling alone. If you do use a taxi, be sure to use a reputable one connected with the hotel you're staying at. Motorcycle taxis are also available for $3 to $20, depending on the distance traveled, but be sure you are provided a helmet, and insist on safety, as Santo Domingo traffic can, at times, leave much to be desired.

Ferries and boats can be a fun option, though a little expensive. Peddle or scoot around Santo Domingo with a bike or moped for about $16 a day.

A privately-owned bus is one of the better ways to go. They are air conditioned and passenger-friendly, with free cookies and coffee. Some even show billingual movies. 

Car rentals are available, but be advised that traffic in Santo Domingo is horrendous. Motorbikes dart between larger vehicles, stoplights are generally ignored, streets are poorly marked, and signage is only in Spanish. So, unless you know your way around and speak the language, think twice about this option.