How to create road intersections with curves? I'd like to create a "curve" at the place where 2 roads intersect, instead of just having unrealistic blocky intersections, so how could I do that the easiest way?

Basically, instead of this   

...I want something like this, that is not blocky



Also, is there a way to snap nurbs paths to this intersection somehow or would I just have to move it here and there until the road (nurbs) fits the intersection model?
One way could be,perhaps,using subdivision surfaces, creasing straight edges... sort of