According to AAA, 37.1 million people are expected to hit the roads this Memorial Day weekend, two million more than last year. Drivers are going to notice the license plates on other vehicles as they go, seeing ones from other states or unusual vanity ones. When they pull over, there’s bound to be a few vehicles without front plates. Is that even legal?

Not in the State of Illinois. According to the Secretary of State’s website, a front registration plate is required on all vehicles registered in the state, as is one in the back. The story is the same in Iowa, although there are exceptions for vintage vehicles. Wisconsin also requires front and rear plates, as does Missouri, although there are exceptions for vintage and commercial vehicles.

Currently, 21 states allow drivers to use only a rear license plate, according to Autolist:

  • Alabama
  • Alaska
  • Arizona
  • Arkansas
  • Delaware
  • Florida
  • Georgia
  • Indiana
  • Kansas
  • Kentucky
  • Louisiana
  • Michigan
  • Mississippi
  • New Mexico
  • North Carolina
  • Ohio
  • Oklahoma
  • Pennsylvania
  • South Carolina
  • Tennessee
  • West Virginia