Judy is correct.
I worked in NYC for over 20 years and commuted from here.
The bus runs along Rte. 22 & Rte. 28. The walk down the mountain to Rte 22 is not for pedestrians. I agree. Too dangerous.
If you take the train, the Raritan line to the Bound Brook station, you can catch a cab to Warren. 10 min. ride.
There is a NYC bus line but has no stops in Warren. You would still need transportation to the bus stop.
Here is the NJ transit link http://www.njtransit.com
I live and work in town...and there are no buses, that i am aware of, that will take you into Warren.
i believe there are buses that run along Rt 22...but that is a far walk (and dangerous) walk, in my opinion, from there. Check out NJ Transit for routes.
I will try and think of any other solutions.
Let us know what you find.