Traffic is bad everywhere in the DR. lol
Even Punta Cana now see traffic jams. That's what happens when the people without vision take control, though in Punta Cana is more of a lack of planning. In Santiago, Santo Domingo, and many other areas is more of inadequate planning than a total lack as what happen in Punta Cana (outside private developments).
Case in point, when Joaquín Balaguer built Churchill Ave in Santo Domingo in the 1970's, it was greatly criticized because how it look then was a major avenue built in the middle of nowhere. For many years you could lay down and sleep on the road with no risk of being runover by anyone. It was mostly empty fields with grass and trees on both sides. Traffic lights were lacking too mostly because they weren't needed. One of the names given by the critics was "the sumptous avenue" since it look like a complete waste of money. Balaguer was crazy, didn't know what he was doing, a fool. Today, no one thinks that about Churchill Ave, instead every avenue in SD should had been as wide as Churchill Ave including avenues that are avenues in nsme only like Defillo Ave. Turns out Balaguer was able to imagine what the future will be and if it wasn't for people who lacked vision, he would had achieved much more on this front. He is also the reason why SD has large parks like Mirador Sur, Norte, Este; a botanical garden, a zoo, an acquarium, etc. Then highly criticised by those without vision, today highly greatful they were created.
After spending much time researching the case of Churchill Ave, I'm convinced the intense criticism the building of this avenue greatly reduced the building of other wide avenues in SD. Imagine how much worst traffic would had been in SD if the few wide avenues that exist would had never been built!
Now you have to buy or expropiate many properties, destroy many buildings, etc if you want to expand an avenue into an actual wide avenue. In many cases this is impossible. Back then much of the current Santo Domingo (and every city, town, and village in the DR) was a clean slate ready for good planning from the start.
Look at Cabarete. That's basically a one road village! Do I need to say more?