A Study of the Traffic Safety at Reduced Conflict Intersections In Minnesota PDF Download

Author: Derek Leuer
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 42

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Author: Max Moreland
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 62

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Between 2010 and 2020, 49 Reduced Conflict Intersections (RCIs) were installed on Minnesota Department of Transportation (MnDOT) roadways. The RCI is an alternative intersection layout that is intended to provide safety benefits by limiting the number of points within an intersection that two or more vehicle paths might intersect. Both a before-after analysis at RCIs and a cross-sectional analysis comparing RCIs to untreated intersections were conducted. With the installation of an RCI, both analyses yielded statistically significant decreases in fatal and serious injury crashes, angle crashes, and fatal and serious injury angle crashes. Statistically significant increases in rear-end crashes were found. Both analyses showed no significant changes to sideswipe crashes or total crashes. Based on these results, severity shift in crashes has been seen at the RCIs in Minnesota. The overall number of crashes have not changed, but the high-severity crashes have been reduced while property damage crashes have increased. The large decreases in severe crashes at RCI locations indicate the RCI can be an effective safety treatment.

Author:
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 64

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Kimley-Horn, under contract with the Minnesota Department of Transportation (MnDOT), has conducted a review of guidance documentation on the design and operation of Reduced Conflict Intersections (RCIs), with a particular focus on signal-controlled RCIs. In addition to synthesizing information from a variety of sources, MnDOT also interviewed representatives from the Texas Department of Transportation (TxDOT) and the North Carolina Department of Transportation (NCDOT)—the two states with the most implemented signalized RCIs in the United States at this time. This document summarizes the findings of this literature review, and is intended to be used as a working best practices guidance document for the design and operation of signalized RCIs in Minnesota.

Author:
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 42

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In the US, some states have begun to address rural high-speed intersection crashes by physically restricting minor-road crossing movements (left and through turns) to simplify driver decision-making in terms of gap acceptance (the extent to which drivers will be able to utilize a gap in traffic of a particular size or duration). These treatments are referred to in Minnesota as reduced conflict intersections (RCIs). Within Minnesota’s rural corridors, introduction of RCI design has been successful in preventing severe crashes; however, the unusual design has been met with some apprehension from operators of agricultural equipment and large trucks. This, in combination with a resistance to the unfamiliar, has created a desire for more information regarding RCI configuration safety impacts for these types of vehicles. In response to these concerns, this study collected and evaluated large vehicle operational behavior at a set of RCIs and at similar standard control intersections in Minnesota. The researchers collected data in 2015 using a portable video trailer array and metrics on truck turning movements at three RCI intersections in Minnesota and three similar non-RCI intersections, which were proximate to the RCI intersections. The researchers compared travel time, evasive maneuvers, and other metrics for this study. The researchers found no evidence that validated concerns expressed about large vehicle operation at RCIs. Exposure time was not increased at U-turn locations and evasive maneuvers were lower than at control locations.

Author: Max Moreland
Publisher:
ISBN:
Category : Roads
Languages : en
Pages : 0

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Between 2010 and 2022, 83 J-turn intersections were installed on Minnesota Department of Transportation (MnDOT) roadways. The J-turn is an alternative intersection layout that is intended to provide safety benefits by limiting the number of points within an intersection that two or more vehicle paths might intersect. Before-after analyses at J-turns and control sites were conducted and compared. With the installation of a J-turn, the analyses found decreases in fatal and serious injury crashes, angle crashes, and fatal and serious injury angle crashes. The large decreases in severe crashes at J-turn locations indicate the J-turn can be an effective safety treatment. The analysis also found J-turns have lower crash rates for key crash types as compared to low-volume interchanges and rural, high-speed signalized intersections.

Author: Timothy A. Chalupnik
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ISBN:
Category : Low-volume roads
Languages : en
Pages : 90

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Category :
Languages : en
Pages : 13

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Crash and traffic data were requested for known reduced conflict intersections (RCI) locations in six states: Maryland, Minnesota, Mississippi, Missouri, North Carolina and Wisconsin. Five states provided data.

Author: Derek Leuer
Publisher:
ISBN:
Category : Traffic circles
Languages : en
Pages : 36

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Author: Max Moreland
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Category : Road markings
Languages : en
Pages : 0

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Between 2018 and 2019, MnDOT installed a lane constrictor design at 66 side-street, stop-controlled intersections in Minnesota. The lane constrictor design narrows the lane width for mainline approaches via a striped median with centerline rumble strips. By narrowing the mainline lane, the goal of this design is to encourage mainline traffic to slow down as it approaches the intersection. The striped median also provides greater separation between mainline directions and draws more attention to the location of the intersection. Following the installation of lane constrictors at MnDOT intersections, overall crash rates have seen little change but there have been decreases in fatal and serious injury (KA) as well as fatal and all injury (KABC) crash rates. These results indicate the addition of lane constrictors have a positive impact on crashes by reducing the severity of crashes, swapping injury crashes for property damage only crashes.

Author: Mark Wagner
Publisher:
ISBN:
Category : Cyclists
Languages : en
Pages : 0

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By the end of 2022, nearly 450 roundabouts were installed on Minnesota roadways. An evaluation of traffic safety at roundabouts published by MnDOT in 2017 showed substantial decreases in fatal and serious injury crashes for all users at intersections after installation of a roundabout. The safety effects of roundabouts are largely due to geometric design practices that reduce the speed of motorized vehicles as they approach and travel through the intersection. The purpose of this evaluation is to determine if the safety effects seen in the 2017 evaluation still apply to roundabouts with higher levels of use by pedestrians and bicyclists. This evaluation conducts a before-after analysis of 95 roundabouts in Minnesota and an analysis comparing roundabouts to untreated intersections. With the installation of a roundabout, this study finds that the before-after analysis results in a 40% decrease in all severity injury crashes for all roadway users, a 70% decrease in fatal and serious injury crashes for bikes and pedestrians, and a 15% decrease in total pedestrian bike and pedestrian crashes. The results of the comparison analyses suggest roundabouts have better safety performance than through-stop and traffic signal-controlled intersections and similar safety performance to locations with all-way stop control. The results of this evaluation thus indicate that roundabouts can be an effective safety treatment for pedestrian and bicycle crashes.