Minge, Erik

Revisions to the appendices of Clear Roads project CR17-02, "Specifications to Standardize Plow Blades with Carbide Inserts."

Many agencies use snowplow blades with carbide inserts to remove snow and ice from their roadways. While carbide inserts are effective at extending the service life of plow blades, there is variability in carbide quality and in the specifications used by each agency in their procurement. This project developed a set of standard specifications to improve this procurement process. Project tasks included a literature review and surveys of both winter maintenance agencies and snowplow blade manufacturers. Follow-up interviews and a site visit to a plant that manufactures these blades provided additional insight into the challenges and opportunities in creating a standard specification. The standard specifications developed cover the chemical composition and the metallurgical, mechanical and physical properties of the carbide inserts. In addition to these technical elements, the specifications include a general set of testing and inspection procedures that can be used to accept or reject a lot of carbide inserts. Separate specifications were developed for inserts with a trapezoid shape and bullnose shape. By putting these standard specifications into practice, winter road maintenance agencies can realize better performance in their plow blades and possible cost reductions as manufacturers can streamline their manufacturing and inventory processes to more efficiently prepare blades to a single set of specifications.

This report summarizes the state of the practice in the application of advanced technologies to winter road maintenance operations. Information was captured through a combination of literature search, surveys, and interviews with key stakeholders. Several promising technologies were identified as areas of interest. These areas include connected automated vehicles, mobile sensor systems, driver assistance systems, enhanced/next generation MDSS, “big data” platforms, data visualization, and video analytics. Use cases for each technology are detailed along with recommendations for potential deployments in both near term and over a five-year planning horizon.

Mobile RWIS technologies are still relatively new to the market, with only a few early-adopting agencies deploying them, primarily in testing situations. This study provides a comprehensive and comparative analysis of four commercially available mobile RWIS sensors. The sensors in the study include: Lufft’s MARWIS, Teconer’s RCM411, High Sierra’s Mobile IceSight, and Vaisala’s DSP310. Testing was completed in two phases. Phase I focused on the accuracy of different sensor parameters when compared to a known baseline. These tests took place at the MnROAD testing facility, a test track containing a variety of pavement types operated by the Minnesota Department of Transportation. Phase II was conducted in “real-world” settings on active roadways. Sensors measured the environment along a set route in live traffic in a variety of weather conditions. The study compared the sensors’ performance while measuring air temperature, surface temperature, relative humidity, surface condition, water film thickness, and friction. The evaluation also compared qualitative aspects of the sensors such as installation methods. The project found that overall, sensors performed similarly across all parameters. This report ranks sensors by accuracy, but the absolute differences in values used to determine rank are often very small. The study also developed standardized recommendations for various mobile sensor parameters. While differences across sensors and the high variability in their readings make establishing universal standards difficult, some commonalties were found. The report includes a suggested matrix of a few basic levels categorizing grip, surface state, and mobility impact. Project completed for Clear Roads Pooled Fund program, #TPF-5(353).

The Minnesota Department of Transportation (MnDOT) launched the Minnesota Bicycle and Pedestrian Counting Initiative in 2011; a statewide; collaborative effort to encourage and support non-motorized traffic monitoring. One of the objectives of the Initiative was to provide guidance related to monitoring bicycle and pedestrian traffic. This manual is an introductory guide nonmotorized traffic monitoring. The manual describes general traffic monitoring principles; bicycle and pedestrian data collection sensors; how to perform counts; data management and analysis; and the next steps for bicycle and pedestrian traffic monitoring in Minnesota. The manual also includes several case studies that illustrate how bicycle and pedestrian traffic data can be used to support transportation planning and engineering.

Investigators created a manual to help MnDOT and local agencies implement counting programs, which can be used to evaluate safety and use of bicycle and pedestrian facilities. The first edition of this manual was published as a draft version. The final version is Report 2017-03.

Conventional methods for detecting vehicles for permanent travel monitoring stations have relied on detecting physical attributes of vehicles without correlating these with the specific vehicles and/or motor vehicle freight operators. However, by using a license plate reader camera, information can be gathered and cross referenced to other known data related to the specific vehicle assigned to the license plate. This could provide additional tools for enforcing overweight vehicles or targeting enforcement communication with freight carriers that consistently violate weight limits. The analysis conducted during this project compared machine-read license plates to manually collected license plates. The license plates were read as vehicle travelled highway speeds in a generally uncontrolled environment. Analysis is also provided that correlates hours of direct sunlight with accuracy of the automated reader. A second analysis was conducted as an effort to improve the accuracy of the Minnesota Department of Transportation's weigh-in-motion classification scheme and bring it in line with the Department's classification scheme for automatic traffic recorder stations (sites with axle-based detection that do not collect weight information).

The Minnesota Local Road Research Board, MnDOT, and SRF performed an evaluation of a portable weigh-inmotion (WIM) system at several locations throughout Minnesota. The system was developed at the University of Minnesota-Duluth and offers roadway designers a low-cost method for obtaining vehicle load distribution data across the state's road network. To deploy the system, the weigh pads of the system were temporarily affixed sensors across the roadway lanes. As vehicles passed over the weigh pads, pressure sensors within the pads detected the weight of vehicles and the system recorded the data for later analysis. Traditional methods for travel monitoring generate traffic volume and classification data, but weigh-in-motion systems give designers a more accurate idea of current and projected traffic loading demands. SRF's testing provided implementation refinements that were incorporated into the system. During the two-year deployment process, the portable WIM system was installed under a wide array of environmental conditions to demonstrate the system's capabilities. Data generated by the system was analyzed. The Final Report details system deployment, calibration, and system accuracy.

While most vehicle classification currently conducted in the United States is axle-based, some applications could be supplemented or replaced by length-based data. Common length-based methods are more widespread and can be less expensive, including loop detectors and several types of non-loop sensors (both sidefire and in-road sensors). Loop detectors are the most frequently deployed detection system and most dual-loop installations have the capability of reporting vehicle lengths. This report analyzes various length-based vehicle classification schemes using geographically diverse data sets. This report also conducted field and laboratory tests of loop and non-loop sensors for their performance in determining vehicle length and vehicle speed. The study recommends a four bin length scheme with a fifth bin to be considered in areas with significant numbers of long combination vehicles. The field and laboratory testing found that across a variety of detection technologies, the sensors generally reported comparable length and speed data.

This phase of the project focused on conducting field tests of selected non-intrustive sensors to determine their accuracy for volume, speed and classification by length and classification by axle configuration. The project also identified deployment issues and costs associated with the technologies.