Consider this fact: during the 10-year period from 2001 to 2010, over 400,000 people were killed in vehicle crashes in the United States. That is an average of 110 deaths on our roads every day for 10 years. It should go without saying that if something could be done by planners and engineers to save lives, then it is our obligation to take action.
What if private corporations owned & operated those same roads? Society would NEVER stand for that! Where is the incentive to move Toward Zero Deaths? FHWA advocates designs that are proven life savers. The engineering community responds by routinely ignoring those life-saving applications for reasons that include political pushback, potential construction delays, and indifference. All examples of unethical behavior, in my opinion.