No, I didn't read the article. The Examiner web site is unusable for somebody with any concern at all for privacy and malware avoidance.

Bus doors are not done in any particular way due to regulations. It's up to the OEM and the buyer. If the buyer wants it done a particular way, it's only money. So what's the deal with "plug doors?"

I've seen buses with: folding doors (most older ones, and even some newer ones; simple top track, easy to repair, minimal space lost in the opening when open), pivoting doors including those that turn in (the most common) and out (unusual these days, but common on older Greyhounds and the like), and "plug" doors that move out and to the side when open (see: GM/Nova RTS buses, old Trailways cruisers, and some current over-the-road buses) which are a maintenance pain but work, and eliminate encroachment within the door opening. Any of them work. It's a matter for choice and engineering.

Insisting on one type of door can affect what bus makers can bid, because not all types will work in a given bus design. Is Muni looking for an excuse to lock some company(ies) out of bidding on a future contract?