Missing the point big time.
Former Sec. of Labor Robert Reich wrote a book about his time as a Cabinet Secretary, 'Locked in the Cabinet'. He relates it's a bizarre world where many layers of bureaucracy and security hamper top government officials from understanding the real world. Anything that's presented to a senior government official at a tour or conference or a visit comes wrapped in the presenter's point of view and you can bet is only there to further the presenter's objectives.
I don't think Buttigieg is trying to virtue signal a green lifestyle. He's trying to experience and learn. I applaud the new Secretary of Transportation for getting out there in traffic on a bike. Even if it was just a couple of miles one day, it's more real-world than him going to France and Japan on junkets, collecting photo ops riding high-speed trains.