Although the Bruce Highway between Townsville to Cairns is a very busy and well travelled highway, it is not a very good highway in my experience.
The Bruce Highway between Townsville and Cairns is a two lane highway for about 95% of the trip, with very few places to safely overtake. About 1/3rd of the highway has no shoulder and no place to pull over, unless you want to drive your car into a cane-field.
The trip from Townsville to Cairns is about 350km, but it takes over 5-hours to drive it. You will want to make sure to fill up your car with petrol in either Townsville or Cairns before undertaking the drive as it’s a long drive and it’s more expensive to purchase petrol in the small towns between Townsville and Cairns.
There has been talk for years from the politicians about upgrading The Bruce Highway in North Queensland, but we will wait and see when or it it finally happens.