Let's be honest. Driving in the DR is not the same as driving at home. There are lots of very poor drivers on the road. There are many unlicensed drivers. There are many drivers who do the most unexpected things at every opportunity. There are many vehicles on the roads that do not have working lights, are in poor mechanical shape and wouldn't be allowed on the roads at home as they are just simply unsafe. It is not uncommon to come across farm animals, domestic animals and pedestrians on the roadway at all times of the day and night. At all times of the day it is not a rare event to encounter drivers who have had too much to drink and are heading to their next fiesta. Vehicles here have two speeds - stopped and full throttle. They pass on blind curves, hills and on the shoulder of the road. If two lanes aren't enough, they create a third and or a fourth lane.
Driving here during the day when visibility is perfect requires your full attention and a lot of local driving experience to fully appreciate the complexity of navigating the local highways and byways. Driving at night especially late at night when you are tired, can't see very well, are unfamiliar with the road you are driving (potholes, breaks in the pavement, debris on the road and whatever other hazards turn up from time to time) is just not worth the increased and substantial risk.
My rule of thumb: If you absolutely have to go somewhere at night and you absolutely cannot wait until morning, then it's pretty darned important and may well be worth doing. However, if your main consideration for driving here at night is to save money, the convenience of getting to where you want to be as quickly as possible, or some other silly a$sed self justification then just don't do it. Find a place to stay for the night, consume some libations to temper your disappointment of being somewhere that you don't really want to be and get a good nights sleep. Tackle the travelling the next day. After a long day travelling and negotiating airports and all that that entails, hopping into an unfamiliar car and speeding off to your resort of choice in the wee hours of the morning is just plain bad decision making.