Induced demand is unmet demand. Rural towns have no problem getting head of demand by building more. It is only in dense cities that nobody builds enough roads to meet the unmet demand for roads.

Of course I didn't mention cost above. A rural area can meet its demand with a cheap asphalt two lane road. A city would need dozens of levels of bridges at a much higher prize to get ahead of demand. Which is why cities should look to transit which is not cost effective for rural areas.