To fully apprize the Legislature of the potential impacts of access management, the Minnesota Department of Transportation (Mn/DOT) has gathered information and conducted research in order to make recommendations covering a wide range of interrelated land use planning, engineering, and legal practices to maximize the operational efficiency and safety of all functional categories of roadways.
The study focused on first identifying and then analyzing a random and statistically representative sample of roadways. The following highlights some of the study’s conclusions:
There is an observed positive relationship between access density and crash rates in 10 of 11 highway categories.
Additional analysis of the crash data in each of the categories revealed that in all cases, roadway segments with the highest crash rates have high levels of access density and segments with the lowest crash rates have low levels of access density.
A review of case studies of 11 access management-related projects (three in Minnesota and eight in Iowa) documented an average crash reduction of approximately 40 percent.
A benefit-cost analysis was completed for the 11 roadway categories. The results are based on a range of estimated project costs and crash reductions and indicate that positive outcomes are possible in every category.
Crash data was analyzed from two different perspectives; a comparison of crash rates on a random sample of the state's highway system and a before/after comparison of crash rates from 11 case studies. The results from each approach suggest a strong and statistically sound relationship between levels of accessibility and crash rates.
The final conclusion addresses the question: Is access management a legitimate public safety issue? All results of the various analyses
suggest that yes; access management is a legitimate public safety issue.
