There is a down side to this. It would use government money to create a new finite resource and there will be battles over it just like spectrum. From TFA:

"Dig once requirements are often opposed by deep pocketed incumbent telephone and cable companies, who build their own infrastructure and would prefer that smaller competitors not have access to cheap and freely available conduit,"

I suspect the big incumbents would simply lease the space and throw their own fiber in there to monopolize this new federally funded conduit. Then some of the maintenance burden falls on the government. Such wonderful corporate welfare well see down the road!