Recent research conducted in a Minnesota city suggests that altering posted speed limits may not immediately lead to a reduction in driving speeds, according to a study conducted before and after the changes. This discovery holds significance for transportation authorities in Minnesota striving to enhance road safety and achieve their Toward Zero Deaths goals.
Gary Davis, a professor from the Department of Civil, Environmental, and Geo-Engineering, spearheaded the investigation, which aimed to evaluate the impact of speed limit adjustments on driving speeds without other alterations to the road environment. The study, supported by the Minnesota Local Road Research Board (LRRB) and MnDOT, was made possible by new legislation allowing localities to set lower speed limits without special authorization.
The study focused on the City of St. Louis Park, where researchers analyzed speeds on over 20 two-lane, two-way roads, some designated for speed reductions and others serving as controls. Measurements were taken before and after the speed limit changes to assess any shifts in driving behavior.
Results revealed only marginal decreases in average speeds following speed limit reductions, with variability observed in speed changes across different roads. Victor Lund, a traffic engineer involved in the project, suggests that adjusting speed limits alone may not uniformly lower driving speeds and emphasizes the importance of considering contextual factors in setting speed limits.
While the immediate impact may be modest, this study lays the groundwork for further examination of how drivers respond to speed limit adjustments over time. Future research could provide insights into evolving driving habits and whether speeds eventually align more closely with posted limits.
