When a child who has just started driving gets a personal breathalyzer for the first time, families tend to start by explaining the numbers on the screen and how to use the buttons. A personal breathalyzer is a tool that measures breath and shows a result, but it is not a device that grants permission to drive. At moments when driving and possible drinking overlap, such as getting home after a get-together or commuting the next morning, a single reading cannot replace the decision about how to travel.
What comes first is not the rules for using the device but a travel promise for days when drinking is possible. It means deciding in advance whether to leave the car behind if you have been drinking or might drink, and whom to contact and how if your plan for getting home falls through. With this promise in place, instead of bargaining over whether to drive after seeing the result, you can choose the next safe step right away.
Set the principle of not driving before any number
The first principle a family should agree on is simple: if you have been drinking, or you are unsure about whether you have been drinking and whether to drive, you do not drive yourself. A personal test result is reference information from your breath at the time of the test, so a promise that uses a particular number as the threshold for setting off is not appropriate.
This principle does not make the breathalyzer useless. Testing can be a way to check your own condition and look back on the choices you made on a day you drank. However, it is safer to treat the device not as a tool for changing your driving plans because the result is lower or higher than expected, but as a reference that supports the decision to hold off on driving and choose another way to travel.
Agree on the plan for getting home and how to get in touch before drinking
If a get-together may involve drinking, decide first, before leaving, whether to take the car. Thinking ahead about whether you can leave the car behind, take public transportation, or get help from a designated driver service or family means fewer rushed decisions right before heading home. It is also good to have a second option ready in case the first plan becomes difficult.
Set the contact promise so that the action is clear, rather than in vague terms. For example, instead of just saying "call if you're in trouble," you can agree that "if your way home falls through, you'll tell us where you are and what help you need." If family members also explain in advance when they can take calls and what else you can look for together when they cannot come in person, the burden of calling in the first place goes down.
| Situation to agree on | Action to decide in advance | Why |
|---|---|---|
| A day with a planned drinking occasion | Decide first whether the car can stay home and how you will get back | So that driving yourself is not left as an option after drinking |
| When the planned way home becomes difficult | Ask the designated family member or contact for help getting home | You can avoid ending up driving while trying to handle it alone |
| When the test result differs from what you expected | Hold off on driving and find another way home | It stops the pattern of testing again and again to change the number |
| When it is hard to use your phone or the app | Use another contact method agreed in advance, such as a phone call | Connection problems will not break the travel plan |
When your child asks for help, help them get home first
When your child contacts you late at night, there are things to check before the test screen or how much they drank. Ask whether they are somewhere they can stay safely, whether they are alone, and what kind of travel help they need. If you make help conditional on sending you the test screen, you may lead them to put off contacting you at a difficult moment.
For instance, suppose your child calls after a late get-together to say that public transportation has stopped and the ride service they planned on is not available right away either. The fact to observe is that the plan for getting home has fallen through. Rather than interpreting this as a question of whether they can drive themselves based on the reading, you can take it as a situation that calls for a place to wait without driving or other travel help.
Possible actions are to contact a family member or acquaintance to help with the trip, or to find a safe place to wait and another way home. The completion criterion for that night is also clear: not driving yourself, and either staying somewhere safe or getting home another way. After they are home, you can talk about why the plan fell through and what to prepare ahead of time for the next get-together.
Leave an alternative way to travel in the next day's schedule too
The fact that you slept or feel fine is not enough to decide whether to drive. On the day after drinking, it is better to leave room to adjust plans for commuting to work or school or for using the car. Even if you used a personal breathalyzer, keep the promise that if you are unsure, you do not drive and choose another way to travel.
This standard should not be a rule demanded only of the new driver. When every family member shows that they leave the car behind after a get-together or use another way to travel, it becomes clear that asking for help is a choice made for safety, not a mistake. Responding after a call by helping with a safe trip, rather than assigning blame, is what turns the promise into actual behavior.
App records are not data for calculating when you can drive
The DATECH AF-40BT supports both standalone use and pairing with a smartphone app, and its guidance mentions a function for saving test results. Even when you use the app, it is appropriate to treat the records as supporting material for looking back on personal drinking habits and travel plans. Do not use accumulated records to calculate when a particular person can drive, or as grounds for relaxing the promise when a certain result appears.
If family members decide to look at records together, they can agree, only to the extent needed, on which results to share and when. For example, if someone repeatedly takes the car to get-togethers or their plan for getting home often falls through, use that as a prompt to change the travel plan before the next get-together rather than focusing on readings. There is one promise to teach before the breathalyzer: when drinking and driving might overlap, do not reach a conclusion alone based on a number, and choose a way home that does not involve driving yourself.
※ Self-test results from our products are provided as reference information only. Official enforcement standards and testing methods may vary by agency and equipment, so self-test results may differ from enforcement results, and the company accepts no liability for enforcement results.
