Electronic tolls in Portugal

AndrewN

Last year I enjoyed travelling on almost deserted motorways in Portugal moving down the west coast from N to S. Couldn't understand why there were no toll booths but the penny eventually dropped. Have been expecting a fine to land on the doormat but none
has materialised I'm pleased to say. Will be doing similar trip in April this year so tried to make sense of the current regulations - incomprehensible. Do I take a chance or is it best to avoid the electronic toll roads?