The vast majority of DWI arrests in Manhattan are made by the NYPD. The police officer will either claim that you violated a traffic law and will pull you over to determine if you have been drinking. The police focus their efforts in areas where there tend to be in areas where there are a large number of restaurants and bars.
Once th DWI arrest has been made, you will be transported to a testing center where the police will ask you to take a breathalyzer. You have the option under New York Law to either take the test or not. If you do not, a refusal hearing will be scheduled to determine if your license will be suspended for one year. After taking these tests, you will be transported to central booking and arraigned before a judge. Most people arrested of DWI for the first time will be released without bail. You will then have to come back to court to address the charges and either plead guilty or go to trial.