HORN OK PLEASE is a phrase commonly painted on commercial vehicles like trucks, in India. The purpose of the phrase is to alert a driver of a vehicle approaching from behind to sound the horn in case they wish to overtake.
But unfortunately, no one knows the real meaning behind it and drivers keep painting it behind their trucks and as some convention or a traffic rule. Although the origin of this phrase is ambiguous and no single meaning can be strongly attributed, still there’re few popular stories that one can find on the internet:
- In the early days, most of the trucks in India were manufactured by the TATA Group. During these times, Tata Oil Mills Ltd. came up with a new brand of detergent called OK. And to market their detergent, they used the motor medium very effectively by painting OK in the middle of HORN PLEASE. But this story has no evidence that this detergent ever existed in India.
- During WW II trucks were often run on petrol and kerosene when there was a shortage of diesel. Petrol, being highly unstable, would cause the trucks to explode at the slightest accident. Hence a warning would be painted on the back saying HORN PLEASE, ON KEROSENE. Gradually this became a norm and ON KEROSENE got abbreviated as OK.
- Yet another explanation is that the OK is separate from the HORN PLEASE. The OK is kept there in big, bold letters, to allow the drivers from behind to realize that they were OK and alive, thus preventing them from rash behavior; besides, the fact that they can read the OK is indicative that they are keeping an appropriate driving distance.
- Since most highways had single lanes earlier, there was always a risk of running into oncoming traffic, especially when you’re behind a truck. The OK had a bulb right over it. When one honked, the truck driver would check if there is any oncoming traffic. If there wasn’t, he would light the bulb and you are okay to overtake. This practice just ebbed away with time, multi-lane highways, and well-lit roads.
HORN PLEASE was never mandated by law to be painted on vehicles. Maharashtra has banned it in the state.
There’s no proof about how this started but it’s a good source of income to the painters who paint it, since time immemorial.