University of Utah review debunks ‘Roadblocks to Quality of Life’ paper used to hamper traffic calming in Salt Lake City
“Liveable Streets and the Quality of Life”, a new report by the University of Utah’s Metropolitan Research Center, states, “The evidence is overwhelming. Traffic calming is not a roadblock to quality of life. It is one of its strongest foundations”. The report was authored by Reid Ewing, Alessandro Rigolon, et al.
The report begins with a chapter tearing down the paper ‘Roadblocks to Quality of Life’ by University of Utah professors Daniel Mendoza and Mark Jansen. The paper was used by the Utah Legislature to justify the 2025 SB195 bill, which forced Salt Lake City to get permission from UDOT for traffic calming road projects on collectors and arterials. The Livable Streets report is thorough in its condemnation of the Mendoza paper, “After a comprehensive review of federal guidance, peer-reviewed research, and real-world case studies from cities across the United States, this report finds those claims to be inaccurate, misleading, and unsupported by credible evidence.”
The Livable Streets report reviews over 700 studies and shows that traffic calming “reduces total crashes by 20–60 percent and severe or fatal injuries by 40–75 percent” with the most benefit coming from road design improvements such as road diets and speed bumps. Additionally, it looks at 40 case studies in cities across the US to show how traffic calming reduces crashes, reduces speeds, and improves quality of life.
The executive summary concludes:
“The evidence is overwhelming. Traffic calming is not a roadblock to quality of life. It is one of its strongest foundations. Leading professional associations that provide guidance for transportation planning in the United States such as the Institute of Transportation Engineers (ITE) and the American Society of Civil Engineers (ASCE), have explicitly endorsed traffic-calmed, safer streets, supported by foundational work like Ewing’s Traffic Calming State of the Practice (1999), published by ITE, and the U.S. Traffic Calming Manual by Ewing and Brown (2009), published by ASCE and supported the U.S. Department of Transportation. Decades of research and real-world practice do not support a debate nor leave room for doubt about whether traffic calming works. That question has already been answered repeatedly and conclusively. The only question now is not if, but where, how, and how fast communities should scale up these life-saving interventions. Legislators and policymakers should reject misleading critiques and rely instead on the extensive, consistent, and credible evidence documented in this report. Safer streets are more livable streets, and traffic calming is one of the most effective tools we have to achieve them.”
The Legislature is doubling down in 2026 with SB242, which would take away even more control of Salt Lake City’s streets and hand it over to UDOT, while requiring unsafe 12’ travel lanes, and threatening to remove bus lanes and protected bike lanes on 200 S, 300 W, and 400 S.
Livable Streets and Quality of Life should be mandatory reading for any legislator voting on transportation bills. According to the cover of the report, it was prepared for the Salt Lake City Transportation Division by the University of Utah’s Metropolitan Research Center. However, Salt Lake City Communications Manager Sofia Jeremias offered this comment on the report’s origins, “Salt Lake City did not execute a contract for the research. Our understanding is that discussions were had between the former transportation director and Reid Ewing. At that time, Salt Lake City was exploring the best options to fulfill the requirements for a mobility plan as outlined in SB 195. The City has still not executed a contract for this work, has not completed a review, and did not authorize its release.”
Download the report here:
MRC U of Utah – Livable streets report
