The sat-nav, the work phone, on call, the child in the back, driving for a living, and the driver beside you

The rule is short and lives can be complicated. Here are the cases readers will raise, each in turn.

The sat-nav. A phone in a cradle showing the map is legal and, kept at eye level and set before you move, is about as safe as a phone in the car gets. The risk isn't the map. It's the tap. So the map goes in the cradle and the rule is that it never gets touched on the move. If it sends you wrong, drive on and let it recover, and if it can't, pull over. What you don't do is hold the phone in your hand to look at the map, which is the knee with a road on it.

The work phone. Two phones don't change the rule, they double it. Both go out of reach. If your job requires you to be reachable by phone while driving, that's a hands-free call answered by voice and kept short, and you're in chapter 7 territory, taking a known cost because your job asks it. Say so to yourself, and take fewer than the job strictly needs.

On call. If you're genuinely on call, doctor, engineer, carer, then the two-call rule is your channel and the standing message is your arrangement. Calls ring through. Messages wait. If the job sends its emergencies by text, that's a conversation to have with the job, because a text you must read within a minute and a car you must drive are two instructions that can't both be followed, and it shouldn't be you who has to choose at fifty.

The child in the back. The water bottle goes down, the toy's out of reach, someone's crying. That's the passenger version of the peek and it has the same answer, which is that anything needing your hands or eyes happens at the kerb. A child who's dropped a bottle can survive four minutes. A child who learns that things get picked up when the car stops has learned something useful. And a child who's old enough to hold the phone is old enough to be the navigator, which gives them a job and the phone a place.

Driving for a living. If you drive all day, the drive setting's auto reply is doing your standing message a hundred times a day, and the cradle is doing your map. The peek is a much bigger part of your day than most people's, which means the risk is multiplied more often and the licence is your income. Six points is a different thing when it's your job. The rule is the same and the reason to keep it is larger.

The driver beside you. You're the passenger and the driver's phone is on their knee. Chapter 14 said the norm in the car is a lever, and you're it. Look up covers the phone across a table, and this is the same move in a car. One plain sentence, not a lecture. "Can I do the phone? I'd rather you drove." Most people hand it over, because being handed a reason to put it down is easier than being told to. If they won't, you've said it, and you say it again next time. The child in the back is listening to that too.