Traffic Flow Modeling, Simulation, and Signal Timing Plans Evaluation of the Miller Hill Corridor

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Date Created
2002-12
Report Number
P2003-02
Description
Traffic flow study of the Miller Hill corridor on Highway 194 between Arlington Avenue and Haines Road, the most heavily traveled and congested roadway in the Duluth area. The study includes preliminary data collection using a non-intrusive Remote Traffic Microwave Sensor (RTMS), traffic flow modeling, traffic simulation and development of an efficient traffic signa l light timing plan. The author develops a reasonably accurate model to estimate traffic flow, which is used in association with the RTMS and a database system to conduct real-time traffic simulations. Results of the simulation were used to develop a traffic-signal optimization plan with Synchro 5.0 software. Discussion of problems faced and how improvements could be made through further research. The author concludes with a proposal that recommends the adoption of the newly developed signal-timing plan to alleviate the traffic congestion on the Miller Hill corridor.

Traffic Safety Evaluation of Signalized Intersections with Retroreflective Backplates in Minnesota

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Date Created
2024-01
Report Number
2024-04
Description
Between 2016 and 2021, MnDOT installed retroreflective signal backplate borders at 116 signalized intersections in Minnesota. Retroreflective signal backplate borders are intended to further increase visibility of the signal head both during the day and at night. The goal of installing retroreflectivity to backplates is to reduce crashes at the intersection by drawing more attention to the current phase of the signal. Backplates with retroreflective borders are listed as a Federal Highway Administration Proven Safety Countermeasure with a listed safety benefit of a 15% reduction in total crashes. With the installation of retroreflective signal backplates on MnDOT signals, the changes in crash rates were not found to be statistically significantly different from similar locations that did not have retroreflective signal backplates. These results indicate there has been little impact on crash rates in the few years after the installation of retroreflective signal backplates.

Driver Comprehension of Flashing Yellow Arrows

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Date Created
2023-12
Report Number
2023-42
Description
In 2009, the FHWA’s Manual on Uniform Traffic Control Devices (MUTCD) introduced the flashing yellow arrow (FYA) traffic signal as an alternative to circular green (CG) to indicate permitted left turns. The FYA is arguably a more intuitive indication that left turns are permitted but not protected and, in addition, the FYA signal heads can support time-of-day changes between protective and permissive left -turn phasing. In 2019, a Research Needs Statement stated that “Research is needed to examine driver comprehension of flashing yellow arrows in different light arrangements and the role of signage.” Our objective in this project was to assess drivers’ understanding of FYA signal indications and to see if the presence or absence of “Left Turn Yield” signs affect gap acceptance. This was accomplished by conducting an online survey of drivers regarding their understanding of FYA signals and by carrying out a field study of drivers’ gap acceptance at a set of Twin Cities intersections.

The Effect of Color in Guidance of Traffic at Interchanges

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Date Created
1964
Description
This paper will describe a 1963 study designed to evaluate further the use of color systems in guiding traffic through highway interchanges. The study was an outgrowth of a similar study conducted in 1959 which suggested that reflectorized color systems could be considered effective in reducing driver problems related to nighttime visibility conditions. As with the 1959 study, traffic stream characteristics were measured before and after the color treatment was installed, and roadside interviews were conducted to obtain driver's reactions to the treatment.

Vehicle Spray Pattern Study

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Date Created
1966-08
Description
A study performed by Davis and Fitzpatrick of Minnesota Mining and Manufacturing Company, in conjunction with the Minnesota Highway Department in 1952-1953, measured changes in reflectivity of highway sign materials due to "spray" and "splash" on a two-lane, rural highway with turf shoulders. The report, entitled "Sign Placement to Reduce Dirt Accumulation" is presented in HRB Bulletin 89, "Night Visibility", 1954. The purpose of this study was very similar - to investigate the pattern of spray from passing vehicles with respect to determining the optimum lateral and vertical placement of milepost markers for an Interstate-type highway with wider, paved shoulders.