On a recent trip to Boston, I saw this generous bike parking shelter, with card-controlled door:
And while on that same trip to Boston, I stayed in a hotel built on air rights over a commuter rail line and freeway. The hotel windows were thick, and sealed. Noise intrusion was minimal and I slept fine. For one night, OK; but I wouldn’t want to live above the freeway or rail line.
At the present time, there are no intentions of selling or leasing air rights over any of the Ottawa’s new LRT lines, as the additional construction cost doesn’t warrant competing for that land — yet. It would make it easier to build on the air rights some day if the two tracks were separated a few feet, to allow for building support pillars, but we don’t plan to do that, even in high value locations, or for lower-value buildings like garages.