The Department for Transport receives regular data from Network Rail and operators about the proportion of customers wearing face coverings on trains. The Office for National Statistics also conducts a weekly survey to track the proportion of people declaring they wear a face covering on public transport. Their survey shows significant public support for the measure - of those adults who had used public transport in the past seven days, 89% had worn a face covering while doing so across all of Great Britain. This rate was the same in England.
To help encourage enforcement of the requirement, Police and TfL enforcement officers have been deployed across the network to support frontline transport staff. Not everyone can wear a face covering, for various reasons, which is why we would not expect 100% compliance with the policy.