Car passengers MUST wear a seat belt/restraint if one is available, unless they are

ركاب السيارة يجب عليهم ارتداء حزام الامان / المثبت إذا كان متوفرا، ما لم يكونوا

Explanation: If you have adult passengers it is their responsibility to wear a seat belt, but you should still remind them to use them as they get in the car. It is your responsibility to ensure that all children in your car are secured with an appropriate restraint.

Category: Arabic - Safety and Your Vehicle

References: The Official DVSA Guide to Driving: Section 2, Highway Code: Rule 99