An interlock, an alcohol interlock device installed in a vehicle, controls engine starting based on the result of the breath test the driver performs by blowing into the handset. The AF-i1 consists of a handset that measures breath and a control box that handles signals on the vehicle side, and it stores usage events such as test results, vehicle ACC, and engine starts. So the approval indication on the screen should be read as a result produced by the test and start control process the device is responsible for.
Especially in settings where several people share vehicles or drive on dispatch assignments, it is easy to treat "approval" and "ready to drive" as the same thing. However, the device's approval means the breath test procedure was passed and the conditions for start control were met. Actually being ready to drive is a state judged only after separately checking whether the person who will drive, the vehicle's condition, and departure preparations are in order. The key point is that the two judgments answer different questions.
The approval indication is the device's judgment
The AF-i1 is designed so that the engine will not start if the driver's test result exceeds a set threshold. Conversely, if an approval indication appears, it means the device has entered a state that allows the engine to start within that test and control flow. This indication is not a certificate that every safety condition of the vehicle or the readiness of the driving assignment has been checked.
For example, the device does not judge who will actually drive the vehicle off, whether there are people around the vehicle, or whether the cargo or dispatch details have changed. If you mistake these items for being included in the device's approval, you may skip things the device does not check. Conversely, skipping the interlock test because the vehicle inspection is done also mixes up separate verification procedures.
Split the departure decision into three different questions
Before departure, rather than looking only at the device screen, the decision becomes simpler if you separate what each check answers. Whether the device approved answers whether the interlock's test and start control procedure was passed. Confirming the actual driver is a separate check of whether the person who took the test and the person who will drive are the same, and whether the conditions for carrying out the driving work are in place.
| Category | What you want to confirm | Next action based on the result |
|---|---|---|
| Interlock status | Whether the screen shows approval, wait, or error | If the indication is anything other than approval, stop the departure decision and record what is shown |
| Actual driver | Whether the person tested and the person who will drive are the same | If the person has changed, do not carry over the existing approval; check the procedure again |
| Vehicle and departure environment | Whether there are any problems around the vehicle, with the vehicle inspection, or with dispatch preparation | If any item is unfinished, decide on departure after that preparation is done |
This table is not meant to weaken the approval indication but to make clear what it covers. Rather than having drivers memorize every item at once, a fleet manager can consider keeping the interlock result and the vehicle and dispatch checks in separate fields on the pre-departure checklist. That way, there is no confusion later about at which step departure was stopped.
If the driver changes after approval, it is not the same approval
A situation in which another person takes the driver's seat after the test is a typical case where you must not link the approval indication directly to being ready to drive. The interlock controls the engine start based on the breath test result, but there is no basis for considering that test to apply to the person who later takes over as driver. If the actual driver has changed, it is right to operate so that that person carries out the device's normal procedure.
As a hypothetical example, suppose that in a logistics vehicle, A took the test and got an approval indication, but just before departure, B was assigned to drive. The facts to observe are two: "there was an approval indication on the screen" and "the actual driver changed to B." Here, the approval should be read as a result of A's test, and the possible action is to have B go through the set test procedure again. The completion standard for this situation is reached when B's procedure result and the checks of the vehicle and departure environment are all in place.
This distinction is also needed to prevent attempts to use someone else's test. The AF-i1 is described as having a function that detects whether a person is testing directly, based on the temperature, humidity, speed, and strength of the breath, and a function that detects cases where the vehicle is driven without an approved test. The point is not to find ways around the detection results the device records, but to operate so that the actual driver and the test procedure match. Only then does the meaning of the records become clear.
If approval appears but the engine does not start, separate the screen from the vehicle response
If you saw an approval indication but the vehicle did not respond as expected, it is hard to conclude right away that the problem lies with either the device or the vehicle. The important observations here are what message or symbol was actually shown on the screen, when it appeared, and how the vehicle responded at ACC or engine start. If you rely on memory and only report "I got approval but it didn't work," it is hard to narrow down what to inspect.
As a hypothetical example, suppose a driver confirmed the approval screen and then tried to start the engine, but the engine did not start. First, keep the vehicle safely stopped, and note the screen indication, the time it occurred, and the vehicle's response when starting. Next, notify the person who adjusts dispatch about the delay, and pass the inspection of the device and vehicle to the installation or technical support channel. The completion standard is a state in which the screen information and vehicle response have been passed on and the case has moved into the inspection procedure without arbitrary setting changes or wiring tampering.
The AF-i1 is a product that takes part in start control by connecting the control box to the vehicle through installation wiring. So if a user tries to change the approval state or touches the connections to find the cause, the original symptom may change and inspection may become harder. Rather than trying to fix the situation with repeated start attempts, it is more appropriate to report the observed facts separately.
Records do not decide departure for you
The AF-i1 stores test results and events related to vehicle ACC, engine start, and tampering, along with date and time information, and the logs can be managed and downloaded with dedicated software. These records are data for seeing which tests and vehicle events occurred on the device at a given time. The fact that a record exists does not by itself mean all departure conditions for that trip were met.
A manager can set a method of recording each fact separately, rather than lumping the approval screen, the actual driver, and vehicle departure preparation into one sentence. For example, if you separate the subject and the action, such as "there was an approval event on the device, the driver was replaced, and the vehicle inspection was completed separately," the scope of later checks becomes clear. The start approval indication is one of the starting points for the departure decision. Actual readiness to drive can be confirmed only when the checks outside the device have also been completed.
