Townsville is a city in Australia.
South towards Brisbane
The intersection of A1 and A6 is a good spot for heading south towards Brisbane. There is a big lay-by right after the light, enough space for a truck to pull over. Take the bus from town center to get there (207 I think), and get off after you pass Woolworths.
South towards Brisbane and Sydney West towards Charter Towers and North towards Cairns
If you like trucks or straight long rides that BP station is for you! http://www.exploroz.com/Places/76724/QLD/Townsville_BP_Truckstop.aspx To get there you can catch a bus from CBD (207,208,209) to Oonoonba or Wulguru and ask the driver to tell you where to get off for BP station (you will have to walk there maybe five more minutes). The trucks pullover pretty much 24h though the best time is from early morning till 7-8pm. From my observation Blunners trucks are going south-north directions. Trucks with loader (like for sand or something) are mostly going West and Lidsay goes mostly North. The rest you just have to ask. There are also passenger cars coming in during the day so try them too! I used this stop few times and once I was waiting just 2 hours the other time 14 so it depends on your luck :) Don't walk around the station, stay near the entrances and ask drivers on the way out as the staff will get annoyed otherwise. Sometimes u can take a shower if the truckers will leave the door open at the facilities (normally u need a key) If you will get stuck over the night go behind the parking space. There will be a building with some grass and gravel behind it, I slept there and it was OK. Be patient as a lot of truckers will say that they can't pick you up because of the insurance policy bullshit. Sooner or later you will get a ride! Good luck !
Another possible hitching spot is near Deeragun, takes a while to get there from central by bus (about 4 dollar. There is a bp and shell station plus woolworths and coles shopping right next to the bruce highway heading north.