If you need help with the Elmsford detour, I can help, I live right near there.But yes, the trail down to the city is easy and well paved for the most part, although from Yorktown to Briarcliff there are some patchy parts. Also, immediately after the detour in Elmsford there is a bit of a sketchy part of the trail and sometimes there is broken glass across it (I have gotten a flat on it twice). From there it should be smooth sailing. Also, if you want another route, you could head down through CT to Kensico Dam in NY and pick up the Bronx Bike trail (paved) there and it will also take you down to the city.