Template of Varying width

I am trying to create a template that varies with the width of the road. The road starts at 16.5' and then transitions to 11'.  I was thinking of creating alignments of the Edges of Pavements and using them as targets. Am on the right path or is there a better way. 

If the alignments of edges of pavement theory makes sense, how do I define that in my templates.

Thanks.

ken