I asked at a truck stop as you enter Grafton coming from the Pacific Highway which was the best way to either Narrabri or Armidale. I was told the northern route to Narrabri was very hilly, very narrow winding roads and the route to Armidale was better.
Well 200K's later and countless ups and downs and so many hairpin bends I was very glad to get to Armidale. Only saw one car and one motorbike on the way.
I drive a 7.6 meter MH flat towing a Suzuki Grand Vitara and it was a slow trip using lots of fuel. I thought it was a very scenic route but I would not recommend towing a caravan or even a 5th wheeler on the route unless you had to. Took around four hours and lots of very slow hairpin bends. I would hate to have met something big coming the other way.
As I live in Grafton, everytime I head towards Armidale or Tamworth I always go via the Gwydir Highway to Glen Innes then turn south, about 65km's longer but a better route to take, Rod
