SRF Consulting Group Inc.

Minneapolis, MN, United States

SRF Consulting Group Inc.

Minneapolis, MN, United States
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Ryan C.,SRF Consulting Group Inc.
Transportation Research Record | Year: 2017

Executive Order 12898 and subsequent U.S. Department of Transportation (DOT) orders require all state DOTs to complete environmental justice analyses to identify disproportionately high and adverse effects of programs, polices, and activities on minority populations and low-income populations. Many analysis techniques have emerged in practice and academic literature, but no official guidance has designated a preferred analysis approach. The passage of the Fixing America's Surface Transportation Act introduced a number of new freight provisions for state DOTs, including a requirement to develop state freight plans to be eligible for funding through the National Highway Freight Program. This paper reviews the existing guidance for environmental justice analyses and documents the application of this guidance to an environmental justice analysis for the Minnesota Statewide Freight System Plan. The plan provides strategies and a policy framework for statewide freight stakeholders to guide planning efforts and investments in the state freight system. The paper concludes with a discussion of further considerations, strategies, and challenges facing freight planning practitioners in future freight environmental justice analyses.


Minge E.,SRF Consulting Group Inc. | Petersen S.,SRF Consulting Group Inc. | Kotzenmacher J.,Office of Traffic
Transportation Research Record | Year: 2011

The third phase of the project on evaluation of nonintrusive technologies for traffic detection is a pooled-fund study in which field tests of selected nonintrusive sensors were conducted to determine their accuracy for volume, speed, and classification by length and by axle configuration. Sensors were evaluated in a variety of traffic and environmental conditions at two freeway test sites, with additional tests performed at both signalized and unsignalized intersections. Emphasis was placed on urban traffic conditions, such as heavy congestion, and varying weather and lighting conditions. Although previous tests evaluated sensors' volume and speed accuracy, the current generation of nonintrusive sensors introduces robust classification capabilities. New technologies, such as ground-mounted laser sensors and improved radar, contribute to this improved performance. Overall, the sensors performed better than their counterparts in previous phases of research for volume and speed accuracy. However, the additional classification capabilities had mixed results. The length-based sensors were generally able to report vehicle lengths within their tolerances, and the axle-based sensors provided accurate interaxle measurements, but significant errors were found in relating these data with a standardized classification scheme, such as FHWA's 13-class scheme. Agencies must perform independent analysis of their classification schemes to determine whether nonintrusive sensors will provide acceptable results.


Davis G.A.,University of Minnesota | Moshtagh V.,SRF Consulting Group Inc. | Hourdos J.,University of Minnesota
Transportation Research Record | Year: 2016

The goal of this research was to develop safety-related guidelines for timeof-day use of permissive left-turn phasing that could be implemented with flashing yellow arrows. This effort required describing the variation in left-turn crash risk throughout a representative day and was accomplished by developing statistical models that related the hourly risk on an approach to left-turn demand, opposing traffc volume, and a classifcation of the approach with respect to operational and geometric features. The models were then embedded in a spreadsheet tool that allowed signal operators to enter-for a candidate intersection approach-a turning movement count and a classifcation of the approach according to speed limit, left-turn protection, and sight distance availability. The user receives a prediction of how the risk of left-turn crash occurrence varies throughout the day, relative to a user-specifed reference condition.


Weinblatt H.,Cambridge Systematics Inc. | Minge E.,SRF Consulting Group Inc. | Petersen S.,SRF Consulting Group Inc.
Transportation Research Record | Year: 2013

Vehicle classification data are an important component of traffic-monitoring programs. Although most vehicle classification conducted in the United States is axle based, some applications could be supplemented or replaced by length-based data. The typically higher deployment cost and reliability issues associated with collecting axle-based data as compared with length-based data present a challenge. This paper reports on analyses of alternative length-based vehicle classification schemes and appropriate length bin boundaries. The primary analyses use data from a set of 13 Long-Term Pavement Performance weigh-in-motion sites, all in rural areas; additional analyses are conducted with data from 11 Michigan Department of Transportation weigh-in-motion sites located in rural and small urban areas and one site located in an urbanized area. For most states, the recommended length-based vehicle classification scheme is a four-bin scheme (motorcycles, short, medium, and long) with an optional very long bin recommended for use by states in which significant numbers of longer combination vehicles operate.


Eyler D.R.,SRF Consulting Group Inc.
Transportation Research Record | Year: 2011

The selection of the appropriate geometry and traffic control for intersections on high-speed arterial highways often requires balancing increased highway user costs with attempts to control construction costs. Providing a safe design that is cost-effective is always a primary consideration in deciding on a solution. Another issue is that one form of intersection and traffic control may be optimal during peak traffic times on an average day but may not have sufficient capacity for extreme peak times such as those for events or on recreational routes. Alternatively, those same controls can cause needless delay when traffic is lighter. Examples include traffic signals that operate 24 h/day and roundabouts that require all traffic to slow dramatically, regardless of the amount of conflicting traffic. This study presents a group of new alternative intersection designs designated as reduced-conflict intersections. This study describes those designs and their associated traffic control, which consists of a demand-based traffic signal system. This study then presents the results of a comparative analysis of this new type of intersection along with other designs, including a conventional intersection with signal control, two forms of roundabouts, and the super street intersection. The results of the study show that the reduced-conflict intersection may be an effective addition to the toolbox of intersection designs.


Minge E.,SRF Consulting Group Inc. | Petersen S.,SRF Consulting Group Inc.
Transportation Research Record | Year: 2013

Although most vehicle classification conducted in the United States is axle based, some applications could be supplemented or replaced by length-based data. Common length-based methods, including loop detectors and several types of nonloop sensors (both side-fire and in-road sensors), are more widespread and can be less expensive. The most frequently deployed data collection method is by loop detector, and most dual-loop installations can report vehicle length. This paper examines field and laboratory tests of loop detectors and nonloop sensors for their performance in determining vehicle length and vehicle speed. Field testing was conducted at four locations in Minnesota and South Dakota. Ten commercially available sensors were evaluated. The testing results indicated that across a variety of detection technologies, the loop detectors and nonloop sensors generally reported comparable length and speed data. The research also examined various loop configurations and found that 6-x 6-ft loops performed similarly to 6-x 8-ft loops, although 6-x 6-ft quadrupole loops performed poorly for vehicles with high beds because of the loops' relatively small magnetic field. Loop detector performance was found not to degrade with the variety of lead-in wire lengths that were tested. Laboratory testing conducted with a loop simulator confirmed the field testing and found that loop detector data are generally repeatable.

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