 A study by the National Highway Traffic Safety Administration in 2009 found that US 9 was the deadliest highway in Dutchess County, with 47 fatal accidents on the road in the 1994–2008 period.Police in the town of Poughkeepsie blamed it on the increasing commercialization of US 9 south of the city of Poughkeepsie.US 9 has had 19 suffixed routes bearing 17 different designations.