The guest: Dr. Timothy Gates, professor of highway design and traffic engineering at Michigan State University.

https://www.egr.msu.edu/people/profile/gatestim

Topics include:

— Why we have speed limits and the history behind them in America.

https://blog.americansafetycouncil.com/the-history-of-speed-limits-in-america/

— Some argue we could go without speed limits and drivers would self-regulate. Those people always cite the autobahn, including a lawmaker in California earlier this year.

https://blog.americansafetycouncil.com/the-history-of-speed-limits-in-america/

— Speed limits on some Michigan freeways increased to 75 mph in 2017 based on requirements adopted by the Legislature. But some critics cite data that shows that the trend toward hiking speed limits has resulted in 37,000 additional deaths since 1993. Charles Farmer, vice president for research and statistical services for the Insurance Institute of Highway Safety (IIHS), says too many people think about the few minutes they're saving by speeding but not about the risk.

https://www.michiganradio.org/post/speed-limit-increases-1993-have-killed-37000-additional-people

— Why officials in Oregon decided to roll back speed limits after some severe crashes in eastern Oregon.

https://www.statesmanjournal.com/story/news/crime/2016/06/08/state-roll-back-speed-limit-increases-eastern-oregon/85592384/

— What research tells us about roundabouts, and why they make sense. Dr. Gates was part of a team studying how to educate the public on safely navigating roundabouts.

https://www.michigan.gov/documents/mdot/MDOT_Research_Report_RC1542_Part1_354968_7.pdf