Flagging in work zones is crucial to the safety of workers and drivers, but it is one of the most dangerous tasks, representing more than one-third of injuries to pedestrian workers. Automated Flagger Assistance Devices (AFADs) are portable traffic control systems that can help to improve safety because flaggers can operate them from outside the flow of traffic. Several states have evaluated AFADs, with generally positive assessments of their effectiveness. While compliance with the AFAD is not universal among drivers, violation rates were lower than red-light violation rates documented in other literature. MnDOT requested information about self-propelling AFADs for mobile work zones, with the specific idea of mounting an AFAD on a remote-controlled caravan mover.
Culvert Designs for Aquatic Organism Passage: Culvert Design Practices Incorporating Sediment Transport
The design of culverts to accommodate aquatic organism passage (AOP) requires an understanding of organism habitat requirements, swimming ability and migration needs, as well as an understanding of how a culvert design will perform in a specific geomorphic context. This report documents existing reports on culvert design for AOP in Minnesota and nationally. It is designed to build upon the work of Hansen et al. 2009 and 2011 to: 1) summarize current aquatic organism passage practices, 2) summarize aquatic organism passage needs for Minnesota species, 3) discuss the importance of roughness or streambed sediment within a culvert in different systems (high, medium, or low slope) in single and multiple barrel systems, and 4) summarize physical experiments of sediment transport and geomorphic processes through culverts.
Performance-Based Specifications for Temporary Erosion and Sediment Control During Construction: A Survey of State Practice
During construction projects, surrounding soils can be disrupted, causing ecological damage through topsoil erosion and pollution of waterways with sediment. MnDOT currently has requirements and inspection procedures to ensure that contractors take measures, typically referred to as best management practices (BMPs), to control this erosion and sediment. Compliance is financially assured via a lump sum payment: Contractors who follow the requirements get paid upon completion of work according to specifications. MnDOT is looking into the prospect of applying more innovative modes of contracting to manage this process. Performance-based specifications would provide rewards for outcomes instead of for simply following MnDOT-required procedures. Contractors could apply new techniques and technologies to address this problem at their own initiative, encouraging faster applications of innovation and making management simpler for MnDOT while granting contractors more discretion. We surveyed other state departments of transportation to assess their experience with performance-based specifications in this area. As part of the survey, we requested guidance for configuring specifications and contract mechanisms, communicating with contractors about erosion and sediment control, and determining whether requirements have been met.
Ultra-Thin Polymer Concrete Overlays for Bridge Decks
Ultra-Thin polymer concrete overlays for bridge decks improve the friction and durability of bridge decks while sealing them against the corrosive effects of deicing chemicals. However, there are concerns that these overlays may trap water in the concrete surface, accelerating deterioration due to freeze-thaw cycles. MnDOT needs more information on the effectiveness of thin overlays in extending the life of bridge structures, the effectiveness of overlays in reducing accidents by increasing friction, and the performance of overlays over time.
State Highway System Classification and Investment: A Survey of Practice
MnDOT is interested in learning how other states align ownership with function, set standards and establish
investment levels for state highway systems. MnDOT is also interested in how changes in the state highway
system over time are reflected in funding priorities and modifications in ownership arrangements.
Integrated Corridor Management: A Review on the Theory and Practice
Integrated Corridor Management (ICM) is believed to be an effective way to reduce congestion and enhance safety by appropriately diverting the traffic to parallel routes containing unused capacity. Numerous ICM conceptual frameworks, models, and solution approaches have been introduced in the literature; some of them have been implemented and evaluated in the field. The aim of this article concentrates on documenting the existing ICM schemes and their field evaluations, and summarizing the lessons learned from the previous research and implementation efforts. We hope the review of the existing literature and the summary of the ICM practice can help readers gather a comprehensive overview of ICM, and inspire further thinking on the improvement of ICM.
Culvert Repair Best Practices, Specifications, and Special Provisions: Task C Research Synthesis
This document contains the results of Task C, Research Synthesis, for the Culvert Repair Best Practices, Specifications and Special Provisions Guidelines Project. These guidelines will provide guidance to MnDOT engineers in making better decisions on culvert repairs. New materials specifications and special provisions will ensure adherence to standardized practices and increase the effectiveness and longevity of repairs. Focus will be on repair of centerline culverts of 24-inches to 72-inches in diameter.
The Minnesota Department of Transportation (MnDOT) currently completes traffic counts, classification counts, and speed counts using a number of sources. These include road tube counters, permanent Automatic Traffic Recorder (ATR) stations, permanent Automatic Detector Recorder (ADR) stations, weigh-in-motion sites, and portable ATRs, specifically using Wavetronix SmartSensors. All of these detections methods require power, but the needs vary greatly depending on the type of detection system. The permanent stations utilize hard wired or ―grid‖ power from local power companies. The cost of this can vary but getting onto the power grid is deemed to be worth the effort and cost to have a reliable source of power for locations that will be collecting data every day of the year for many years, such as at permanent ATR and ADR stations.The focus of this research will be on portable power sources to power the Wavetronix SmartSensor HD system that MnDOT currently employs for some of their traffic counting efforts.
Collecting and Managing Traffic Data on Local Roads
MnDOT is investigating alternatives to this primarily centralized approach to gathering traffic counts. To support this effort, this report examines traffic counting practices on local roads from five perspectives:
Current MnDOT traffic counting practices
Traffic counting technologies appropriate for temporary deployment
Literature review of traffic counting practices on local roads
Surveys of statewide participants in MnDOT's traffic data collection program (initial and supplemental surveys)
Survey of state DOTs' local road traffic data collection practices
Traffic Forecasting on Trunk Highways in Nonmetropolitan Areas: A Survey of State Practice
Traffic forecasting plays an important role for MnDOT in corridor planning, geometric design, pavement design, safety analysis, benefit/cost analysis, access management, and environmental analysis and mitigation. In previous decades, Minnesota has seen steady growth in vehicle miles traveled. However, in recent years VMT growth in Minnesota has been flat and declined by 0.5 percent from 2009 to 2010.
MnDOT is interested in learning how other states are dealing with what appears to be a nationwide trend in a leveling off or decline in VMT, and what forecasting methods are used by state DOTs to project traffic volumes in nonmetropolitan areas with a population under 50,000.
Mitigating Highway Construction Impacts with Transit
This TRS is provides a summary of research done on how to mitigate the impacts of highway construction projects through the use of transit and what strategies can be used to retain riders it after a highway construction project is done
Traditionally, Minnesota's posted speed limits are determined using the Institute of Transportation Engineers methodology as well as other considerations. The ITE methodology uses field measurements to evaluate roadway segments for the speed at or below which 85 percent of free flowing vehicles are traveling. MnDOT has observed that the ITE methodology often determines a higher operational speed for two-lane rural highways than MnDOT believes is warranted by other engineering and safety considerations. Further, MnDOT is being asked to justify posted limits of 55 mph when statutory limits for such roadways in Minnesota are 65 mph.
Consequently, MnDOT would like to identify alternative methods used for determining posted speed limits that produce greater compliance by motorists.
Minnesota counties have been actively implementing new design and construction techniques for multiple projects in recent years. In June of 2011, the Local Road Research Board (LRRB) discussed and approved preparing a synthesis report to document several of these projects.
Scanning tours have previously been conducted to investigate bridge design and construction methods used in other states. Staff from the MnDOT State Aid Office and the Bridge State Aid Unit, representatives from the Minnesota County Engineers Association, and FHWA have participated in the scans. Several of the technologies identified during these scans have since been applied to local bridge construction on Minnesota projects, and are included in this synthesis.
Far -Field Testing of Noise Wall Effectiveness: Survey of State Practice and Literature Scan
Before performing a formal investigation involving such "far-field" testing to confirm MnDOT's view that far-field noise levels do not increase with the installation of noise walls, CTC & Associates was asked to review noise wall testing research and guidance, and contact national experts to determine whether such testing has been performed elsewhere. The scope of this investigation also includes determining how other state departments of transportation have responded to simila complaints. This review doesn't include noise generated by reflection between parallel barriers; Minnesota is investigating this issue by other means.
Impact of Vibratory Equipment to Surrounding Environments during Construction
MnDOT is interested in the conflict resolution process surrounding the impact of vibratory equipment, including impact or damage to property, best practices for public engagement during large projects, educating the public about the potential for damage during construction, and construction in areas susceptible to damage.
A survey of MnDOT personnel, a survey of state DOTs, and a literature search were performed, focusing on MnDOT current practices, and other state DOT practices that address the conflict resolution process for vibration-producing activities such as compaction, pile driving, blasting or pavement breaking.
Cracking in bridge decks has been a main concern of bridge designers and owners for decades. Various contributing factors have been identified but their relationships are not fully understood.
The Minnesota Department of Transportation has collected data during construction of bridges between the dates of approximately July 2005 and present. The data includes construction practices and environmental conditions during construction, and bridge inspection results. To prepare for a larger study to analyze this data, this report examines previous studies for the causative factors of bridge deck cracking, a Transportation Research Synthesis (TRS).
Use of Social Media by Minnesota Cities and Counties
Minnesota's Local Road Research Board (http://www.lrrb.org) is interested in knowing the extent to which Minnesota counties and cities are using social media: Which social media outlets are they using? How are they using them? Of particular interest are transportation-related communications through social media channels.
LRRB requested a nonscientific scan of counties and larger to help establish the scope of social media use by local governments for transportation purposes throughout the state of Minnesota.
This research reports on whether and how other states gather and analyze data or estimate mode share (transit, bicycling, or walking) for travel statewide. This research found that many states do not provide information on current bicycle and pedestrian mode share. Those states that do report this information, report either Census data or from their own travel behavior inventories if they are at all current. (read more)
This report looks at how state DOTs and regional-level MPOs (Metropolitan Planning Organizations) coordinate funding estimates for long-range plans. It looks at whether state DOTs are directive about the funding estimates used by MPOs in their long-term plans and if so, how they do this. It also looks at how MPOs accommodate uncertainty in their funding estimates. This study also looks at how MPOS select projects and how state DOTs interact in these processes.
Snow Plow Cutting Edges for Improved Plowing Performance, Reduced Blade Wear, and Reduced Surface Impacts
This report aims to provide MnDOT Maintenance and local agency winter maintenance units with a concise research synthesis on snow plow cutting edge research. This research synthesis provides a single source with which maintenance managers may use in decision making in regard to purchase and use of snow plow cutting edges.
Effects of 24-Hour Headlight Use on Traffic Safety
Daytime running lights—generally low-wattage headlights that turn on automatically when a vehicle’s ignition is started—are a safety feature intended to reduce multiple-vehicle crashes during daylight hours by making vehicles more conspicuous to other drivers. In some countries, such as Canada, they are required to be standard equipment on all vehicles manufactured; in the United States they are permitted but not required, and were standard equipment on about 27 percent of new vehicles manufactured in 2005 (NHTSA, 2008).
Potential Benefits to the Freight Industry of Distance-Based Road User Fees
As vehicles become more fuel efficient, fuel taxes are producing less revenue for road construction, operations and maintenance. As a consequence, states are exploring replacing these taxes with other userbased revenue sources, such as mileage-based road user charges, also referred to as vehicle-miles-traveled fees. These approaches may also have the benefit of reducing highway congestion if pricing is varied by level of congestion. The commercial freight industry agrees that distance-based pricing, especially as it relates to congestion pricing, has system management and revenue benefits for transportation agencies but is skeptical about benefits to the industry and believes such fees will be more costly than current fuel taxes.
The Minnesota Department of Transportation and the Local Road Research Board initiated a preliminary investigation into the issues surrounding the maintenance, preservation and possible conversion of low-volume paved roads to gravel. Rising costs of pavement materials and stagnant or declining funds for road construction and maintenance prompted the agencies to begin looking into issues surrounding the decision to unpave low-volume roads. To assist in the process and to provide
MnDOT and the LRRB with the best, most up-to-date information, CTC & Associates was asked to review the issues associated with the decision to convert paved low-volume roads to gravel roads. This research synthesis highlights relevant research and information related to road surfacing decisions, pavement preservation techniques, cost analysis and current road agency experiences.
Local government agencies create, collect, compile, and store data that also have value to other state agencies, such as the Minnesota Department of Transportation (MnDOT). In turn, MnDOT also is a keeper of information that has value to local government agencies. Local government and state agencies create and maintain their cadastral and right of way data in varying ways and with different systems, and those differences pose one barrier to the sharing of that information. A 2002 initiative to develop a statewide parcel map inventory helped set the stage for several projects to improve data sharing of right of way and cadastral information between MnDOT and local government agencies. Recognizing the benefits of easy access to existing data among agencies, MnDOT began exploring potential solutions for sharing cadastral data between MnDOT and local government agencies. MnDOT relies on maps, deeds, and other right of way records from local government agencies when planning right of way options and acquisition needs. To investigate the potential, MnDOT sponsored a 2004 research project, Enhanced Coordination of Cadastral Data. The research evaluated the potential for sharing of cadastral data and outlined considerations for moving forward. In 2006, MnDOT launched an implementation pilot project in MnDOT Districts 3 and 4, which involved collaborations with local government agencies, technology development, launch of a web-based portal, and training and communication to support use. It also helped demonstrate the possibility for data sharing among state and local government agencies on a broader scale. This TRS highlights the benefits of improving access to data sharing, describes the implementation and research projects, provides an update on the status of implementation, and outlines next steps.
State DOT Experiences with Primavera P6 Project Management Software
Minnesota DOT is considering various project management software applications for use in a range of highway construction activities. One of the applications under consideration is Primavera P6 Enterprise Project Portfolio Management software. The product is now available through Oracle, which acquired Primavera Software Inc. in October 2008. We were asked to survey several state DOTs currently using this application to gather preliminary information about its potential applicability to MnDOT.
CTC approached Oracle to identify states using Primavera P6. The Oracle representative we spoke with thought that the following 13 states were using P6: Connecticut, Florida, Illinois, Massachusetts, New Jersey, New Mexico, New York, Puerto Rico, South Carolina, South Dakota, Texas, Virginia and Washington. We queried DOT research directors for the names of Primavera managers we could interview and were able to identify appropriate individuals in the following state DOTs: Connecticut, Florida, New York, South Carolina, South Dakota, Texas and Washington. We also identified and interviewed the Primavera manager for the Port Authority of New York & New Jersey. Below are the questions we posed, based on input from the Mn/DOT team that is investigating the project management applications. Names and contact information for interviewees are included in the Interview Responses section that begins on page 4.
As part of the development of Minnesota DOT’s Americans with Disabilities Act Transition Plan, the department adopted Public Rights-of-Way Accessibility Guidelines as its primary guidance for public facility design. To fully implement PROWAG, MnDOT will be conducting departmentwide training on both design and policy. The department is developing ADA compliance training for MnDOT staff, local governments and consultants. To assist Mn/DOT in the development of curriculum modules and other training materials, CTC & Associates conducted a “state of the practice” review of relevant reference and training materials from federal agencies, advocacy groups and other state DOTs.
The ability to innovate is critical to an organization’s performance, especially for DOTs confronted with managing a large and complex transportation system. However, like many large organizations, DOTs typically resist change and are slow to innovate.
Minnesota DOT is interested in the steps other states have taken to encourage a culture of innovation among employees, including a work environment, organizational structures and operating procedures that reward exploration of new, more effective approaches to doing business.
We conducted a survey of state DOTs and performed a literature search, focusing on:
Challenges, opportunities and successes in developing a culture of innovation.
Organizational strategies for moving toward a culture of innovation.
The relationship of a culture of innovation to centralized or decentralized organizational structures.
The 2009 edition of the Manual on Uniform Traffic Control Devices includes requirements for the management and maintenance of all roadway signs. Management of large numbers of signs can pose administrative and financial challenges for local road authorities. The Minnesota Department of Transportation is reviewing whether the removal of ineffective traffic signs may be part of an overall sign management strategy and has asked CH2M Hill to prepare a best practices guide for removing traffic signs. In support of this work, CTC & Associates was tasked by MnDOT with performing a literature search and synthesis of research demonstrating the effectiveness or lack of effectiveness of various types of traffic signs on local roads, including low-volume roads.
Effects of Major Traffic Generators on Local Highway Systems
The Minnesota Department of Transportation initiated a study focused on the effects of major traffic generators on local highway systems. Minnesota State University and SRF Consulting Group, Inc. will conduct a major research study on the topic. To assist in that research CTC & Associates was asked to conduct a preliminary investigation focused on large wind farm developments, an increasingly common type of major traffic generators in Minnesota.
The development of large wind farms necessarily includes the movement of very large, oversize trucks carrying wind turbines over county roads. This construction raises several concerns, including pavement damage; indirect impact to the immediate area surrounding the roads; and related costs to local governments to repair and maintain the roads and to mitigate other effects. The preliminary investigation focused on gathering information related to the two main areas of inquiry in the research project: calculating pavement damage and secondary impacts due to large vehicle traffic; and policy options for local governments to recapture the costs of roadway maintenance caused by wind farm development.
Issues of Concern Related to Underground Infiltration Systems for Stormwater Management & Treatment
This Transportation Research Synthesis (TRS) provides an overview of relevant literature, regulations, guidance, and other information related to a specific stormwater Best Management Practice (BMP), underground infiltration systems with sump manhole pretreatment. This TRS is intended to serve as part of the justification to prompt a review of this practice and related practices in the context of a revision to the Minnesota Stormwater Manual (MSWM).
Anti-icing in Winter Maintenance Operations:
Examination of Research and Survey of State Practice
MnDOT is developing an anti-icing guide that will be incorporated into the department’s existing winter training program. The guide will be used by front-line supervisors and managers to better manage their winter operations and by operators to assist them in effectively performing their snow and ice control duties.
To prepare for development of the anti-icing guide, MnDOT asked us to review relevant research to identify existing anti-icing practices, field strategies and procedures, and application rates. We also reviewed 12 transportation agencies’ anti-icing guidelines and procedures to identify current patterns of practice.
Methods and Practices for Control of Canada Thistle
Recognizing the challenges in controlling the weed, Canada thistle, the Minnesota Department of Transportation (MnDOT) and the Minnesota Local Road Research Board (LRRB) have supported research on the topic. This synthesis offers a brief summary of that work and provides additional information about other national and international research, MnDOT methods and practices, other state department of transportation practices nationwide, and research in progress.
Transportation Research Synthesis:
Planned and Unplanned Disruptions to Transportation Networks
The collapse, on August 1, 2007, of the I-35W bridge over the Mississippi River in Minneapolis, abruptly interrupted the usual route of about 140,000 daily vehicle trips and substantially disturbed the flow pattern of the network. In addition to the heavy losses in life and injury, the network disruption has also significantly impacted road-users and reshaped travel patterns in the Twin Cities area, which could generate significant cost due to longer travel distance, higher levels of congestion, and the resulting opportunity losses. According to Minnesota Department of Transportation (MnDOT), rerouting alone could cost individual travelers and commercial vehicles $400,000 daily based on Metropolitan Council planning model. Xie and Levinson (2008) find a lower, but still large, estimate of expected costs to road users, between $71,000 and $220,000 per day. As a result, a significant financial incentive was given to the contractor for the early completion of the replacement bridge. A similar financial incentive was employed after the Northridge Earthquake in California...(read more)
Transportation Research Synthesis: Methods of Estimating the Economic Impact of Transportation Improvements
When confronted with the problem of evaluating proposals for projects involving new highway capacity, public decision makers face a bewildering array of options for anticipating and assessing project-related economic impacts. On one hand, the issue of geographic scale is highly relevant. Local or project-level impacts may be very different from those estimated at regional and multi-regional levels. Another salient issue is that there are many metrics for assessing economic impacts, ranging from direct user benefits and changes in external costs of travel to more aggregate economic indicators, such as employment, income and productivity rates.
Several types of economic benefits arise from transportation improvements:
reductions in travel costs;
more efficient supply chains;
intra-firm scale economy effects (permitting individual firms to through larger scale operations at fewer locations);
agglomeration (including inter-firm scale effects) whereby clusters of competing and complementary firms perform better than firms in isolation; and
re-organizational benefits, where firms can reorganize the way they produce output, and improve quality or even the goods that can be produced thanks to new infrastructure, just-in-time production is an example.
Transportation Research Synthesis: Traffic Calming for High-Speed rural Roadways
The Minnesota Local Road Research Board (LRRB) requested a synthesis of studies that explore the topic of traffic calming for high-speed rural roadways. The Federal Highway Administration (FHWA) offers a description of traffic calming that includes two components:
“The combination of mainly physical measures that reduce the negative effects of motor vehicle use and improve conditions for non-motorized street users.”
“A number of transportation techniques developed to educate the public and provide awareness to unsafe driver behavior.”
The FHWA and the Institute of Transportation Engineers (ITE) acknowledged the challenges in reaching a consensus on a definition of traffic calming in its publication, Traffic Calming, State of the Practices, 1999.
Transportation Research Synthesis: Transverse Rumble Strips
The Federal Highway Administration (FHWA) defines rumble strips “as raised or grooved patterns on the roadway shoulder that provide both an audible warning (rumbling sound) and a physical vibration to alert drivers that they are leaving the lane.” Cities and counties may use rumble strips as means of enhancing safety to help warn motorists to slow down in anticipation of a stop sign or to help warn motorists that they are leaving the roadway or crossing the centerline.
A Synthesis of Research and Resources on Local Road and Bridge Funding for Local Public Works Officials
This project, sponsored by MnDOT’s Research Services Section, is an effort to identify the most relevant, useful, and applicable research on local transportation finance issues for local government practitioners in Minnesota. The editor, working with staff of the MnDOT Library, has reviewed hundreds of documents and other resources in an effort to identify those that have the most potential to directly assist local officials through better understanding of current and alternative funding policies, better awareness of existing analytical tools and other resources, and greater familiarity with available funding sources and procedures.