Police footage shows the moment a lorry driver makes a card payment on his phone at the wheel.
The West Mercia force spotted the trucker on the M40 in Warwickshire.
He was among more than 3,000 drivers filmed from three unmarked lorries in the past year.
From the high vantage point of the “super cabs”, police can look into the windows of passing trucks and gauge how well they are being driven.
The measures form part of a crackdown on dangerous driving on fast roads.
Some drivers have been spotted with their feet up on the dashboard and watching TV.