Please can you explain this statement further ?
“Speeds fell an average of -0.7mph. Experience of the introduction of 20mph limits in other cities is similar. But average speeds are a crude measure of “pace” and “feel” of a road which is so important to active travel and liveability.”

I am completely behind the move to 20mph but are average reductions in speed only really less that 1mph ?

Also – if other streets are becoming ‘safer’ in non 20 mph areas – can that be linked to an effect on over all carefulness of drivers?