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Methods and Practices for Setting Speed Limits (FHWA and Institute of Transportation Engineers)' Identifies four methods for establishing speed limits (Engineering approach, Expert System Approach, Optimization and Injury Minimization). This is the Safe Speed Approach. This report provides practitioners with guidance on how to set speed limits in their jurisdiction without making specific policy recommendations or suggestions. The Safe Speed Approach resulted in speed limits that were at the lower end of the range of speeds enacted by the practitioners. ITE Speed Zoning Guidelines (Institute of Transportation Engineers Committee)' Identifies factors such as geometric design, roadside development, shoulder and road surface characteristics, pedestrian and bicycle activity, speed limits on adjoining highway segments, accident experience or potential that should be considered as part of an engineering speed study. In no case should the speed limit be set below the 67th percentile of free -flowing vehicles. The speed limit should be set to the nearest 5 mph increment to the 85th percentile or the upper limit of the 10-mph pace. No speed zone should be established in a location where 85th percentile speed is within 3 mph of the statutory speed limit. Reducing Speeding Related Crashes involving Passenger Vehicles (National Transportation Safety Board)' The NTSB focused on five measures of speeding: speed limits, data -driven approaches for enforcement, automated speed enforcement, intelligent speed adaptation, and national leadership. They state higher speeds are likely to lead to a higher number of, and more serious, crashes. The Safe System approach in determining other factors leading to safety issues needs to be considered. There is not strong evidence that the 85th percentile equates to the lowest crash involvement on all road types. Managing Speed: Review of Current Practice for Setting and Enforcing Speed Limits (TRB report 254)4 Limiting speed is not the only thing that should be considered for increased safety. Cutting down on impaired driving and safety belt use have higher safety reduction. An increase in the age of the population also has a toll on safety. Congestion also increases driver frustration and encourages unsafe driving. Technology can help with the speed limit considerations. Technology can help the efficiency and effectiveness of enforcement. Advocacy The National Association of City Transportation Officials (NACTO)5 is "an advocacy group of major North American cities and transit agencies formed to "exchange transportation ideas, insights, and practices and cooperatively approach national transportation issues". A NACTO working group recently developed recommendations for setting speed limits on urban streets with the intent of providing an alternative to federal guidance. The result of this effort was a 3-method approach that is outlined in the document "City Limits, Setting Safe Speed Limits on Urban Streets". In addition, the Minnesota Department of Transportation recently conducted a statewide Speed Limit Vision' project. This effort has resulted in a collection of educational and informative data that can be useful for addressing speed related issues. The stated goal is to develop a unified vision related to speed limits that was supported by cities, counties, and special interest groups, as well as public safety and enforcement professionals. The visioning project is based on Minnesota Speed limit history, as well as local and national research. A Technical Advisory Group was formed that included state, county, and city transportation professionals, as well as transit users, pedestrians, bicyclists, public health, law enforcement, and mobility impaired users. 1 Methods and Practices for Setting Speed Limits, FHWA, 2012 2 ITE Speed Zoning Guidelines, ITE 3 Reducing Speeding Related Crashes involving Passenger Vehicles, NTSB, 2017 4 Managing Speed: Review of Current Practice for Setting and Enforcing Speed Limits, TRB,1998 5 City Limits, Setting Safe Speed Limits on Urban Streets NACTO, 2018 9 6 A Minnesota Vision for Speed Limits, MnDOT, 2020 Page 141 of 185