That's a classic example of the highway authority preferring to encourage motorists into head-on collisions than redistribute the space for bus lanes or bike lanes that emergency vehicles could also use to avoid queues.
While I get the point, it's just an old alignment of road that's never raised cause to be revisited. It's hard to imagine a queue forming there. The nearest traffic count point (the other side of Porlock, but still west of Minehead):
Frankly, I'd actually prefer the current layout as a cyclist. Take primary, anyone overtaking should have absolutely no problem finding opportunity to fully move into the central overtaking lane to overtake. Rather than have two half-width cycle lanes on a rural A road.
To put its quietness into context, the A855 on Skye, which is regularly
singletrack, is nearly 50% busier.
Finally, if you look at crash statistics, it does have a couple of serious collisions in the last 25 years, but fatal collisions have occured on different stretches.