Google sheets - Notification IF a cell is highlighted by 2 conditional formattings

Is there a way to generate an alert or a notification WHEN a cell or some cells are highlighted by 2 or more different conditional formattings?Making that the upper conditional formating overwrite the lower one...

This notification should come after selecting a choice from the data validation dropdown menu in A15, F15, P15 and U15, in order to select another car avoiding a crash with the car before or after...

Attached the 2 cases:

• Case OK : each conditional formating highlghted diffrent cells:

• Case NOK : conditional formattings are sharing some cells:

To understand what I mean, here's the example I'm working on:https://docs.google.com/spreadsheets/d/1skYbRolzLWyxMe06Ppd5tLobksQ8gD9dHrBP3dwgZwA/edit?usp=sharing

Thanks in advance for your help