Thus, avail yourself of the subway and taxi cabs. Later at night, express stations and those near nightlife destinations tend to be more populated and safer than others. Don't take chances, however. A cab ride is cheaper than getting mugged and a lot easier on the nerves. Also, much faster.
Subways run less frequently at night, causing some extended, boring waits on station platforms.
Speaking of cabs, they carry up to four people at a time. They all have meters, so there's no need to negotiate a price. Cabs with their rooftop lights lit are available, those with no lights on up top have a fare already. If there are available cabs driving by, they'll swarm. If you'd like them to drive faster, smoother, slower, etc, just ask.