If you hear a fire truck honk three times, this is what it means

Have you ever heard a fire truck honk three times, or use a siren sound that doesn't match that familiar, high-pitched wail?
Hosted on MSN

The Best Truck Train Horns: Honking Loud and Proud

If you've ever heard a train blowing its horn and thought, "Man, I wish I had that for my truck," you're not alone. This wonderful invention made its way from trains onto heavy trucks sometime around ...