The way I like to explain this is that in Transport Canada we have three main pillars: the economy, safety and security, and the environment. If you have those three pillars in balance, en équilibre, then you have sustainable transportation. If I want to push this for safety, for instance, if you want to have absolute safety, stop everything from moving, then you will have absolute safety. The safest day we had in the last 60 years in aviation was September 12, 2001. No aircraft moved. There wasn't a single accident or incident, but that's not good for the economy. It's good for the environment, though. Those three have to be in balance in order to have sustainable transportation.
To answer your question, it's for both: economically speaking and environmentally speaking.