How it looks.

UA had an accident in DEN IIRC where the jetbridge collapsed onto the wing.

Largely because of the limitation of "double bridges" throughout the system. Aircraft parked off-bridge have a greater chance of front and rear boarding as airstairs can be positioned there. At FRA, many of LH's Domestic & European flights are parked at off-bridge/off-site areas.

Traveling around Singapore, S. Korea, and Malaysia, I found two-door boarding made quick work of getting people in the plane.

Almost made me miss a couple of flights because they're so damn good at getting people in. Usually, there's a queue in American cities and you have some leeway to enjoy lounge drinks.

(Astro)Physics: Engineering without the annoying limitations of reality :)

1 - It is not a tarmac. It is called a ramp or more correctly an apron.
Lots and lots of people incorrectly call it a tarmac, when in fact tarmac is a type of asphalt.

2- De-board is not a word.
You can say deplane (preferred), egress, exit or any other bevy of words.

3- Using the forward and aft exit doors is not that common in Europe

kingdom come
 

^ OH bin BP readers: your BP opens only the closest OH bin. You get five seconds to stow your bag :D , then the bin closes.

:td: Pipe dream. People would stand in the aisle waiting for another bin to open, or just stand there until kingdom (or an FA) come.

Is tarmac the type of asphalt used at airports?

Is deboard any better or worse than deplane, a word basically made up for this purpose? Deplane sounds better to the ear now, but I probably sounded just as bad as deboard the first time someone used it.

At the end of the day, no major legacy airline is going to do random boarding or straight seat-assignment boarding, no matter what mathematicians say. They're going to load premium cabin and elites first and then something simple for the GA's to call out after that.

Early boarding is one of those little DYKWIA things that we will absolutely lose our collective sh** about if it gets taken away by any major airline.

To my knowledge concrete is used at most (if not all) airline ramps.
I have never stopped taxiing the aircraft to get out to take a sample. :D

I believe tarmac asphalt was once used at a couple of airports in the UK back in the 60's, for a brief period.
It's up there with air-pockets and black ice, just more things the media reports incorrectly and somehow it develops a life of its own.

if we're being pedantic, why would anyone call the apron a 'ramp' when it is horizontal?

how many people are lots? how frequent is 'common'? certainly ive boarded and deplaned in this manner, in this region, often enough to lose track. or lots of time, if you will :D

Or really innovate (and, no, this is not a joke). Eliminate overheard storage altogether. You're allowed a purse or a murse and nothing more. Check everything else.

that'll only incur longer total time for pax.

i'd take the extra 5 minute penalty on boarding.

And you can pay for all of the electronics and valuables that get stolen from checked luggage.

I don't think it'll make a difference, there's always that one muppet who waits for final call or is late so we all have to wait anyway.