For the tourist that has little or no understanding of the Spanish language, a taxi might be the best mode of transportation (especially for first time visitors) for getting around in Santo Domingo. While English is widely spoken in the city, road signs are usually in Spanish, making navigation a challenge for the foreign language-impaired. 

Driving laws are not strictly enforced in the Dominican Republic. Speeding, tailgating, and driving with dsfunctional vehicles is common. Night driving is especially not recommended for these reasons. But probably the greatest deterrent to driving a rental car is the inhibitive cost of rental insurance. Coupled with the afore-mentioned dangers, the risks of renting a car are simply not worth it. 

Taxi fares are on a fixed rate based on your destination and, though more expensive than the public transportation system, they are generally more comfortable and convenient. Fares are usually posted outside the arrival terminals of every airport, so look for them before jumping into a cab and trusting that the driver is going to be honest. The plain truth is, that some are not and will overcharge the gullible-looking tourist. Also confirm whether the fare is in pesos or dollars. Another option is a limo or private car service; not much more than the taxi's but better vehicles and professional drivers.

If you still choose to rent a car, you will need a valid passport, driver's licence, and credit card. Most companies will take an open voucher on your passport, which will be returned when the car is returned in original condition. A collision damage waiver is essential to avoid paying for damage incurred in an accident. Finally, be sure to inspect the rented vehicle before leaving the lot to insure that all current damage is noted in the paper work.