Labor & Employment Law Daily Wrap Up, DISCRIMINATION—DISABILITY—D. Idaho: Court sides with locomotive engineer in ADA case involving Union Pacific’s color-vision field test, (Aug 20, 2026)

By Ursula Furi-Perry. J.D., MBA

The employee did not have to prove that he could pass a particular color-vision test, only that he could safely perform the essential functions of a locomotive engineer.

A federal district court in Idaho refused to overturn a jury verdict finding that Union Pacific violated the ADA when it terminated a locomotive engineer after he failed the railroad’s color-vision field test. The court rejected Union Pacific’s arguments that the employee was not a “qualified individual” under the ADA because he could not satisfy Federal Railroad Administration (FRA) color-vision requirements and failed to exhaust the FRA’s administrative appeal process. It also concluded that the employee timely filed his ADA action and upheld the jury’s rejection of Union Pacific’s business-necessity and direct-threat defenses (Mills v. Union Pacific Railroad Company, No. 1:22-cv-00143-DCN (D. Idaho Aug. 17, 2026)).

Color-vision tests. Union Pacific hired the employee in 2004 and tested his color vision pursuant to FRA regulations under the Ishihara test, which identifies color-vision deficiencies but does not measure their severity. The employee failed that test, and FRA regulations permit follow-up testing to determine whether an employee who fails the initial screening can nevertheless accurately identify railroad signals. Following his failing test, the employee passed Union Pacific’s follow-up field tests in 2004, 2007, 2010, and 2013, and he began working as a locomotive engineer.

After a 2012 train collision prompted recommendations for improved color-vision testing, Union Pacific developed a new field test known as the “Light Cannon.” The test required an employee standing a quarter mile away to identify 20 signals displayed for three seconds each, and a single incorrect response constituted failure. In 2016, the employee again failed the Ishihara test and then missed five signals on the Light Cannon. Union Pacific denied his FRA certification, making him ineligible to work as a locomotive engineer. The employee unsuccessfully pursued an internal appeal and initially appealed to the FRA before abandoning that process, instead filing an EEOC charge alleging disability discrimination.

After the district court denied Union Pacific’s summary judgment motion, the case proceeded to trial. The employee presented evidence concerning his years of safe work as an engineer and expert testimony addressing his color-vision deficiency and alleged flaws in the Light Cannon. The jury found that Union Pacific violated the ADA and awarded the plaintiff $767,842.18 in backpay. Union Pacific then renewed its motion for judgment as a matter of law.

Procedure. The district court addressed the procedural issue under Rule 50(b) of the Federal Rules of Civil Procedure, discussing whether no reasonable juror could find in the non-moving party’s favor, so that the evidence permitted only one conclusion to the contrary of the jury’s verdict.

Qualification standard. The court first rejected Union Pacific’s contention that the employee could not qualify for ADA protection unless he demonstrated that he could satisfy the FRA’s color-vision testing standards. The ADA defines a qualified individual as someone who, with or without reasonable accommodation, can perform the essential functions of the position, the court explained, distinguishing an employee’s ability to perform an essential job function from an employer’s “qualification standards,” including physical, medical, and safety requirements.

Ordinarily, an ADA plaintiff must establish the ability to perform the job’s essential functions, while the employer bears the burden of justifying a qualification standard under the ADA’s business-necessity defense. Although government-mandated qualification standards can alter that allocation of burdens, the court concluded that FRA regulations did not mandate Union Pacific’s Light Cannon test and instead gave railroads substantial discretion to determine the form of that testing.

Because Union Pacific developed the Light Cannon and chose how to interpret its results, the railroad had to justify the test under the ADA, and the employee therefore did not have to prove that he could pass a particular color-vision test, only that he could safely perform the essential functions of a locomotive engineer. The employee had repeatedly passed earlier field testing, had no history of incorrectly calling signals, and presented expert evidence that his particular color-vision deficiency did not interfere with his ability to identify railroad signals and would not deteriorate over time.

Timeliness. Next, the court rejected Union Pacific’s argument that the lawsuit was untimely because the employee maintained that he never received the EEOC right-to-sue letter. Under controlling Ninth Circuit precedent, an ADA claimant may sue once the EEOC has failed to act on a charge for 180 days, but the 90-day limitations period does not begin until the claimant receives a right-to-sue notice, the court noted. Because the employee denied receiving the notice, Union Pacific could have invoked the mailbox-rule presumption by producing evidence that the EEOC actually mailed it.

Affirmative defenses. Lastly, the court held that the jury rejected Union Pacific’s affirmative defenses. On the defense of business necessity, for example, the employer had to show that the Light Cannon fairly and accurately measured the employee’s actual ability to perform the job’s essential functions. The jury heard evidence of solar glare during Mills’s test, differences between the Light Cannon and actual railroad signals, expert criticism of the test’s design, and evidence that approximately one-quarter of people with normal color vision failed the test on their first attempt. As Union Pacific denied the employee a second attempt, a reasonable jury could conclude that the Light Cannon did not accurately measure his ability to distinguish railroad signals, the court held. Union Pacific likewise failed to establish that the employee posed a direct threat, which required objective evidence of a significant safety risk. The Ishihara test established only that the employee had some degree of color-vision abnormality, while the jury could reasonably find that the Light Cannon was not reliable objective evidence of his ability to identify signals.

Accordingly, the district court denied Union Pacific’s Motion for Judgment as a Matter of Law.

The case is No. 1:22-cv-00143-DCN.

Judge: Nye, D.

Attorneys: Brandon T. McDonough (Casey Jones Law) for Monte Mills. Emma C. Nowacki (Duke Evett) for Union Pacific Railroad Co.

Companies: Union Pacific Railroad Co.

Cases: Discrimination DisabilityDiscrimination IdahoNews