Background: New York City passed a traffic ordinance that prohibited the display of commercial advertising on vehicles using public streets. An exemption in the ordinance was made for ads that were on vehicles that related to the business interests of the vehicles’ owners.  Express Railway Agency violated this ordinance by selling advertising space on their vehicles to unrelated businesses.  The conviction was challenged by Express Railway claiming that the ordinance violated the equal protection clause because the distinction being made between related and unrelated advertising was not justified by the public safety purpose of the ordinance.

Supreme Court: The Court found that the ordinance had a legitimate purpose by advancing the traditional police purpose of public safety. The exemption was valid because it limited the distractions to motorists as intended.  Further, the equal protection clause did not function in an absolute manner, thus a city could ban some advertisements that distracted motorists without being required to eliminate every distraction.  Jackson wrote a concurrence.  He reasoned that invoking the equal protection clause meant that a valid regulation required a broader impact and only reasonable discriminations that related to the purpose of the regulation were permissible.  Since the purpose of the ordinance was to reduce traffic hazards, the city acted within their constitutional power; and the limit created by the ordinance was not arbitrary as it had an appropriate relation to furthering the intention of the ordinance.

Legacy: The case is an example of the rational basis review. The rational basis review is one that the Court relies on to this day when dealing with non-fundamental rights cases.  The test lays out that in cases where there exists a disparity of treatment the Court will search for a rational relationship between the existing disparity and the legitimate government purpose.  So long as there is a rational relationship to a valid state power then the court will allow the law to stand.