The law is outdated, DMV spokesman Derrick Stokes acknowledged Tuesday, but because it is in the driver's manual, it could be a question on the driver's exam. In fact, it is even on a list of practice questions for the test.
And it is not just cars that you are supposed to be honking at. Check out this further bit of guidance from the New Jersey Driver's Manual:
"As you approach a bicyclist, skateboarder or skater, beep your horn as a warning that you are approaching."
Before you follow that law, consider this provision in more genteel Pennsylvania, where honking is for use as an emergency warning.
"NEVER [their emphasis] honk your horn at bicyclists," the Pennsylvania Driver's Manual says. "Horns may startle them and cause them to accidentally steer into your path."
Even New Jersey DMV officials acknowledged that Pennsylvania might have them on that rule.
"We want our motorists to be informed of the law, but we want them to apply common sense when driving," Stokes said.
If you have ever wanted to break the law, this might just be the one to pick.
"I've never ever heard of someone being cited for failure to honk," said Lt. Al Della Fave, an 18-year veteran of the New Jersey State Police.
The DMV's spokesman, who doesn't honk when he passes other vehicles, agreed that there is something risky about following this law.
"In the era of angry drivers, one has to be very careful how he or she uses their horn," Stokes said.
Contact staff writer Mitch Lipka at 609-989-8990 or mlipka@phillynews.com.