1. Southern Pacific Co. v. Arizona, (1945)
2. Facts: The Arizona Train Limit Law of 1912 prohibited operating railroad trains of more than a prescribed length. Reducing the length of the trains was said to increase safety because of less “slack action” which caused trains to behave uncontrollably. However, the length limit required the train operators to run about 30% more trains, and cost Southern Pacific about a million dollars/year in extra costs. About 95% of all rail traffic in Arizona was interstate, and so it affected train operations from Texas to California.
3. Procedural Posture: In 1940, Arizona sued Sourthern Pacific for the statutory penalties for violating the law. The trial court found the law to be an unconstitutional burden on interstate commerce, and further found that it was not justified by local safety concerns because the increase in safety by reducing the slack action was offset by the decrease in safety of more trains. The state supreme court reversed, concluding that a state police law, based on safety, could not be overturned even though it had a substantial effect on interstate commerce.
4. Issue: Whether the total effect of the state law as a safety measure in reducing accidents is too small to outweigh the national interest in keeping interstate commerce free of burdens where a uniform national regulation is needed.
5. Holding: Yes.
6. Majority Reasoning: The general rule is that the states do not have the authority to substantially impede the free flow of commerce where the need for national uniformity in laws demand that the regulation be done at the national level. However, this case lies between the two extremes of clearly needing national regulation, and clearly needing a local police measure. Thus, it calls for a balancing of the state and federal interests. The findings show that the increase in safety is small if at all. Also, if the length of trains is to be regulated, it must be done uniformly for efficiency. Since the Arizona Law is a substantial burden on commerce where a need for uniformity exists, and does not have an adequate police justification, it is unconstitutional.
7. Dissent Reasoning: [Black] thought that the balancing test was best left to the legislature and not the judiciary. [Douglas] felt that the state legislation was adequately tied to safety and thus entitled to a presumption of validity.
