With 91,700 delivery vehicles on the road every day, one of the top concerns for Atlanta-based UPS Inc. is driver safety. So managers thought they were doing the right thing when they barred deaf and hearing-impaired people from driving the company’s largest delivery vans. They based their decision on studies that showed deaf drivers are more likely to get into car accidents.

However, some hearing-impaired employees didn’t see it as a safety policy. Rather they saw it as an arbitrary bar to their career advancement based on the stereotype that deaf people cannot drive safely. To remedy that, more than 1,000 current and former UPS employees and applicants sued the company in a California district court in 1999, alleging the company’s policy violated the ADA and California laws.