Whilst we are talking about traffic accidents and immigration, a British lady I met who was a hotel manager in Bavaro was driving on the highway there one night. Young guy on a moto drove straight in front of her, she had no chance to stop, he died. Her insurance paid RD$ 2 million, that was their limit. Family wanted more money and the case rumbled on forever through the court. She had an Impedimento Salida put in her passport while they were considering whether she was guilty or not, and couldn't leave the country for ages and ages. And then her mother got ill in the UK, she was desperate to go home and couldn't. Yes eventually it all got sorted out, but it took years and years.
Honestly, if you're a foreigner driving and involved in a serious accident where someone dies, it will be real mess. If you can use Uber or get a local to drive, don't risk it. The roads here are too dangerous and the driving is so appalling.