If you currently operate or plan on operating a commercial vehicle a DOT Exam is required,or if your company is designated by the DOT "Safety- Sensitive",DOT Physicals are important because they make sure that you can operate a vehicle safely and make sure there are no current health concerns that would prohibit that,since your job impacts not only your safety but the safety of others.
There are strict guidelines for DOT physicals to make sure that employees are in good health.