True, which is why paved shoulders should not be promoted as purely an investment in favour of cyclists. For example, loose gravel is one of the causes of roll overs when cars drift off the road and drivers overcompensate on the steering. There is also no room for trucks with wide loads to travel on the highway — with the increasing popularity of factory built homes (partly because of the migration of skilled labour away from rural communities) we are going to see more of these monstrous transports using the road. Paved shoulders also make the roadway last longer by preventing edge erosion. And then there's the "small benefit" that cyclists become less of a nuisance to motorists
At roughly $30,000 a kilometre to pave shoulders, the 1,500 kms of Highway 17 really should not cost more than 50 million, something that could see a return in investment within a decade. In the end, the government really has no good reasons not to pave the shoulders!
As this summer's ride was my second time going across the continent from British Columbia, I actually took the south shore of Superior route through Michigan's Upper Peninsula. Most of the roads are better, but in some stretches along M-28 not much better. The terrain is flatter but goes through mostly monotonous forested interior with rare views of the lake.
The cycling advocates in Sault Ste. Marie have mapped out this alternative route
that avoids much of Highway 17 east of the city. I tried it for a abut 60 kms but reverted back to the highway when one part turned into a really rough road and I didn't find my way back on to it.