Yes, all low level IFR ops (below 18000'+ class A) are generally operating on the controlled airspace airways (class E) which are 4 miles wide each side.
Not sure how well the US airspace system applies here. The US have radar coverage to the ground almost everywhere. Their ATC works a lot harder for you (apples to apples comparing terminal area procedures). Outside controlled airspace, they are more comfortable relying on VMC see/avoid, ATC advisories, and TCAS warnings to make it work. It's a fine system once you get used to it.