Before the pedants jump in and point out that the Hidden report (named after Anthony Hidden by the way) is no longer legally binding and individual TOCs will have their own set of guidelines. Those guidelines can very between individual companies and individual depots within said companies, for example intensive suburban work will have slightly different limits to express/intercity work, the numbers listed above are a good ballpark figure.
I would like to add that there are also agreements of how breaks are taken, such as how long a break needs to be, the point within a shift that a break should happen (mostly to stop companies putting the break right at the start or right at the end of a shift) and even what facilities need to be made available to train crew during those breaks. They cant force a driver to eat his sandwiches in the cab during a 15 minute turn around for example.