It may also be driven by a combination of railroad legal departments, insurance companies and OSHA. You can try to regulate a workplace in order to make it safe for a rational sentient being or you can try to make it absolutely idiot-proof. A rational sentient being is relatively unlikely to take an action which may cause injury while an idiot might not hesitate to do so. If the idiot gets hurt and then sues the employer, the outcome might be a large payout and a penalty from OSHA. Therefore, the tendency is to over-regulate the workplace in the name of safety even at the expense of reduced efficiency. Although there may not appear to be an appreciable gain in workplace safety, the objective is to help ensure that if some idiot does get injured on the job it is because a rule was violated and, thus, the employer is not liable.