that is so so wrong
not wholely in favour of overengineered solutions and mandating design but believe dft guideline for a path adjacent to high speed traffic is 2m ideal 1.5m min – reckon that re-used “wobble” strip is less than a metre wide – it simply encourages drivers to pass without pulling out and at 70mph plus!
(and if you ride further out knobbers will pump their horns/pass deliberately close to “police” use of the cycle lane)
the best solution is to narrow the outside lane and move it across and widen the inside lane – this is what dft suggests is good practise for this type of road
then have a short turn into the sliproad crossing at the crossing point
though any road like that really does need a properly segregated cycle lane