United and Delta tried during the pandemic to improve social distancing [1] but switched back once travel came back, and I'm guessing this kind of boarding ended up being slower. It turns out the Southwest way (random boarding) was still the fastest.
>Loading back to front just moves the line inside the plane, but is not significantly faster than loading from the front to the back.[2]
I find SWA the fastest boarding but after boarding is complete there is a 5-10 minute delay from the gate agents delivering documentation to the pilots, as opposed to airlines like Delta where boarding absolutely takes longer but once boarding is complete, the plane quickly leaves the gate. In the end it feels like they take the same amount of time.
To avoid a line forming in the plane, they should board by column, even rows then odd rows. A Odd. E Even. B Odd. D Even. C. D Odd. B Even. E Odd. A Even. People and family together can board together, only if their towards the window counterpart has been called.
Random is mostly the fastest. But I find think southwest is exactly random. As most people tend to sit in the first seats, so southwest turns into a front to back boarding.
One thing nice about southwest is orderly lines.