I would be interested to know if Ryan have recommended max taxi speeds for dry and different max taxi speed for wet and different max taxi speed for contamination...straight line and turns.
As an ex L1011 low vis pilot trained by BA way back in 1975/6... we were thouroughly trained on when to use various taxi speeds and to know the speed limitations...the First Officer and Flight engineer were required to positively monitor the captains taxi speed v the taxi chart and call any deviations by observing a fitted cockpit ground speed monitor during taxi...apart from their other duties...20kts/9knots and 3kts and avoid 120degree turns off the runway remain burned in what remains of my brain.