License plate

A license plate is a small piece of sheet metal with an embossed and printed serial number to indicate that the ownership of a vehicle has been properly registered. Because the government maintains a record of which person has been assigned a particular serial number, the government can maintain accountability for a vehicle without stopping and talking to the operator. For example, parking tickets can be issued for parking violations based on the license plate even if the operator is not present, because the vehicle owner is vicariously liable for any violations.

With the advent of artificial intelligence, computers have been programmed to perform automatic license plate recognition (ALPR). ALPR uses a computer to examine photos taken of vehicles to isolate the license plate number. ALPR can be used with red light cameras or speed cameras to issue tickets for violations without human intervention.

Until the 1960s, states would issue new license plates each year. However, to save money, most states now send an annual decal to be affixed to the existing license plate to indicate that it has been renewed for an additional year.

Plate design

Each state has a sequence number scheme of numbering their plates. These schemes are designed to be different than the neighboring states. (Some states start with letters followed by numbers while others use the reverse.) States design their license plates with a distinctive color scheme and motto. However, motorists are given the option of purchasing "vanity plates" for an additional fee. These plates may include a special motto and use a symbol sequence of the owner's choice instead of the typical serial number.

Both pro-life and pro-choice groups seek to get their supporters to use "vanity plates" expressing their political views. In Henderson v. Stalder, 407 F.3d 351 (5th Cir. 2005), the United States Court of Appeals for the Fifth Circuit held that Louisiana's prestige license plate program that offered pro-life plates but not pro-choice plates could not be challenged in federal court.

In Hill v. Kemp, 478 F.3d 1236 (10th Cir. 2007), the United States Court of Appeals for the Tenth Circuit held that Oklahoma's pro-life specialty license plate charges are "taxes under State law" for the purposes of the Tax Anti-Injunction Act (TIA) and thus the Court affirmed the district court's dismissal of claims of discrimination in offering the plates.

In ACLU v. Bredesen, 441 F.3d 370 (6th Cir. 2006), the Court of Appeals for the Sixth Circuit reviewed the constitutionality of Tennessee's statute making available the purchase of automobile license plates with a "Choose Life" inscription, but not making available the purchase of automobile license plates with a "pro-choice" or pro-abortion rights message.