The largest funeral procession in the U.S. was for President Ulysses S. Grant. More than 1 million citizens lined the streets of Manhattan. The procession stretched for 7 miles, and took 5 hours to pass.

Laws for funeral processions differ by country, and by province or state within the country. Below is a list of the most general rules of funeral processions.

* All vehicles traveling in a funeral procession must be accompanied by a licensed escort. Police were formerly common, but it is now not often in the budget. Usually one escort is assigned for approximately every 10 to 12 vehicles. The lead of the procession is usually a limousine or hearse, though special vehicles are often used for people whose life work involved them. Examples include ice cream trucks, firetrucks and zambonis.

* Funeral processions have the right of way. People are required to yield, and not interfere or cause an obstruction. This said, funeral processions are not immune to traffic laws such as lights and signs.

* Stickers, or colored markers, should be attached to front and rear windows of each vehicle.

* Everyone that's part of the procession is required to have their lights turned on, and some states require the escort to use hazard lights.