It is very obvious, the same driving behaviour on a disused airport, on a highway, in front of a school, in a dense city approaching an intersection, etc… do not correspond to the same driving risk ! And no one can deny it.
If you measure driving behaviour without knowing driving context, it is impossible to compute driving risk. Training drivers not to do severe braking is very dangerous: they will hesitate even if a child surrounds in front of the car. Severe Braking is sometimes absolutely necessary. And that is why car manufacturers develop more efficient braking systems at each car generation (drum brake, disc brake, ABS, EABS emergency assisted braking systems), spending a lot of money for it !
If you take safe driving coaching course, they will teach to break your speed very harshly in case of any doubt. Road Safety should not use “intuition” of non-expert people or “belief”, but science and facts.
Just to make sure that our explanation makes sense, let us compare on a very simple case of urban risky situation (STOP sign) the harsh braking detection and the SafetyNex alert.
– Use case 1 : the driver arrives too fast approaching a stop sign. Instead of anticipating, this driver sees the stop sign at the very last minute and brakes very harshly. It is possible to put a threshold on acceleration value and then detect the harsh braking. This harsh braking detection obviously corresponds to a driving risk, and the figure 1 shows when it happens on the pathway.
SafetyNex predicts the next locations of the pathway, and estimates in real time if driving behaviour is adapted or not to the complexity and singulatities of road infrastructure ahead.
Because SafetyNex cannot predict that the driver is going to brake (the behaviour does not show it), SafetyNex driving risk rises as shown on figure 2.
One can notice that as soon as SafetyNex understands that the driver finally brakes enough to stop the car, then driving risk falls down very quicly. Driving risk rises BEFORE potential accident : first you take risk, and second you may have an accident.
SafetyNex and harsh braking criteria both detect that the driver took risk in such a situation : if you count alerts, you have 1 for harsh braking and 1 for SafetyNex.
What is the difference ? Well SafetyNex anticipates and then SafetyNex can alert the driver a few seconds before stop sign, letting time to slow down, where harsh braking criteria only monitors but cannot be used to alert because it has no anticipation feature.
– Use case 2 : It is exactly the same situation, but the driver doesn’t brake at all
Because there is no braking at all, the detection of harsh braking is not possible, as shown on figure 3 :
This driver that is much more dangerous than the previous one is not detected by harsh braking detection. Harsh braking detection is not effective on this use case.
SafetyNex works exactly the same way than in the previous use case : because it is not possible to forecast that the driver will brake, then risk rises as shown on Figure 4 :
Risk falls down only when situation is left behind : after crossing the stop sign, it is too late for risk assessment, it is an « alea jacta est » situation, you will have an accident or not depending on luck, there no possible anticipation.
. Conclusion :
Everytime that harsh braking corresponds to a real risk, SafetyNex also gives an alert. And SafetyNex still gives alerts in very dangerous situations where harsh braking detection is not effective.
SafetyNex is simply the next generation for driving risk assessment, you can now forget harsh braking detection and leave it all behind.
One more point, SafetyNex risk rises BEFORE dangerous situation, then you can alert driver and ACT on accident rate reduction.
SafetyNex can reduce accident rate by 20% for a regular inattentive driver (your ROI evaluation is easy to do).
