The Minnesota Department of Transportation (Mn/DOT) conducted a two-year study on developing a concept of the Next Generation Road/Weather Information System (NG-R/WIS). This report describes the concept and a prototype implementation of the NG-R/WIS in Minnesota District-1.
Traditional R/WISs offer limited scope of data types, limited communication methods, and proprietary incompatibility problems. The R/WIS in Minnesota District-1 experienced the typical problems of the traditional R/WIS. This project looked a solution to those problems-developing a new layered hierarchical architecture referred to as NG-R/WI.
Four layers--a sensor layer, a data integration, a database layer, and an application layer--form the basis of the NG-R/WIS form the basis of the NG/RWIS. This architecture allowed integration of heterogeneous systems through the data integration layer and provided structured data to applications through a standard relational database and computer networks.
This project developed three applications: web page service, automated voice service, and live stream-video service. The web pages and automated voice services provided solutions for unlimited access from anywhere, unified data format, ease of use, and no requirements of special terminals or software. The live video stream demonstrated integration capability of the system and provided a new class of information. The report concludes with the recommendations and future directions of the proposed NG-RWIS.
The Minnesota Department of Transportation (Mn/DOT) conducted a two-year study on visibility measurement methods using video cameras. This report describes the study's theoretical basis, practical methods, and experimental results.
Among several methods and algorithms developed, the edge decay model along with a proper threshold technique worked best for evaluating daytime visibility. This approach estimates the distance where an object of specified size and shape is no longer distinguishable from the background in terms of edge information. For night time, a constant light source is required to evaluate visibility. Researchers developed a light diffusion model that follows an exponential decay curve.
Researchers determined that the volume of light diffused out of the original source logarithmically correlates to visibility. Mn/DOT implemented day and night algorithms in the field and evaluated them using manual measurements. For daytime, visibilities measured using the edge decay model closely approximated the manual measurements on all types of weather. Unreliability of manual measurements at night made night-time evaluation very difficult. However, research verified that the trend of visibility change obtained by the proposed approach closely approximates the trend of manual measurements.
Collection of vehicle classification data is considered an essential part of traffic monitoring programs. The objective of this project is to integrate the raw classification data generated by the Minnesota Department of Transportation (MnDOT) Regional Transportation Management Center (RTMC) into the existing volume data managed by the Traffic Forecasting and Analysis (TFA) Section under the Office of Transportation System Management (OTSM). RTMC manages a large number of traffic sensors in the Twin Cities' freeway network and continuously collects a huge amount of traffic data. Recently; it added Wavetronix radar sensors; from which length-based classification and speed data are generated in addition to typical volume and occupancy data generated by loop detectors. This project integrates this classification data into the existing TFA volume data; which could save cost and time for TFA in the future by using existing classification data. The project team also integrated the RTMC speed data for the locations where it was available. The final deliverable of this project was a software tool called detHealth_app; from which users can retrieve classification and speed data in addition to volume/occupancy data in multiple formats including Federal Highway Administration (FHWA) format. The detHealth_app program was thoroughly tested and has been successfully used by MnDOT TFA.
The Regional Transportation Management Center (RTMC) at the Minnesota Department of Transportation (MnDOT) deploys a large number of traffic detectors in the Twin Cities' freeway network and continuously collects traffic data. While RTMC mainly uses the data for traffic and incident management; the TFA (Traffic Forecasting and Analysis) office uses the same data for monitoring; forecasting; planning; and reporting of transportation applications. RTMC provides current and historical volume data generated from its freeway network; but it does not provide quality information on that data. The objective of this project was to develop a new tool that can quickly explore the quality of detector data. To allow exploration of data quality; 13 detector-health parameters were computed using raw volume and occupancy data and then they were stored in a relational database. The final detector-health system was implemented as a client server-based system; in that a single server served many remote clients through the Internet. This report provides descriptions of the detector-health parameters; principles applied; server implementation; client software; and some analyses and application examples.
Bull-Converter/Reporter is a software stack for Weigh-In-Motion (WIM) data analysis and reporting tools developed by the University of Minnesota Duluth for the Minnesota Department of Transportation (MnDOT) to resolve problems associated with deployment of multi-vendor WIM systems in a statewide network. These data tools have been used by the MnDOT Office of Transportation System Management (OTSM) since their initial delivery in 2009. The objective of this project was to expand the current conversion capabilities of BullConverter to include more raw data formats from different companies and the current BullReporter functions to include new analysis and reporting capabilities. Data analysis needs change over time; and the members of the OTSM WIM section identified several new functions that would increase efficiency and improve quality of WIM data. This report describes the new reporting and conversion functions implemented in this project.
Building a WIM system around polymer piezoelectric film sensors, called BL sensors, costs only a fraction of the traditional WIM system built around crystalline-quartz piezoelectric sensors called Lineas sensors. However, BL sensors are highly sensitive to temperature, which limits the accuracy of weight measurements. The objective of this research was to investigate the performance of BL sensors head-to-head with Lineas sensors by installing a BL WIM system and collecting data from the same highway. After the test site installation, pavement temperatures were recoded as part of each vehicle record from both Lineas and BL sensor-based WIM stations. The analysis of data collected over 10 months showed that temperature dependency of BL sensors can be removed in terms of average but not variance. More specifically, the average of axle weights after temperature-based calibration was about the same for both BL and Lineas sensors, but the variance was much higher for BL sensors. In conclusion, if BL sensors are used, pavement temperatures must be recorded as part of vehicle records. Then, the weights calibrated based temperature would be as accurate as Lineas sensors in terms of the average but not variance.
A complete portable weigh-in-motion (PWIM) system consists of a pair of weigh-pads (one for upstream and the other for downstream), a controller which translates raw load signals to WIM data, and an optional external battery pack. The weigh-pad dimensions are one foot wide and 24 feet long, covering two lanes. This document describes how to install and remove weigh-pads using the recommended tools and setup of the controller. The operation of controller that includes initial setup and calibration is described step-by-step. The controller stores WIM data in the controller hard disk using a comma separated values (CSV) format; the details of the CSV file naming convention and column formats are described.
The ALERT-2 system was redesigned to mitigate increased roll-throughs. With respect to technological advances, the ALERT-2 system improves many aspects of the basic technologies, providing higher system reliability, easier installation and maintainability, and better self-sustainability through redesign of the renewable energy application. To assess the driver behaviors at the test site, 13 months worth of video data and a survey of local residents were collected. This report describes the system development, implementation, and analysis of the video and survey data.
Installing permanent in-pavement weigh-in-motion (WIM) stations on local roads is very expensive and requires recurring costs of maintenance trips, electricity, and communication. For county roads with limited average daily traffic (ADT) volume, such a high cost of installation and maintenance is rarely justifiable. One solution to bring WIM technologies to local roads is to utilize a portable WIM system, much like pneumatic tube counters used in short-duration traffic counts. That is, a single unit is reused in multiple locations for few days at a time. This way, WIM data is obtained without the cost of permanent in-pavement WIM stations. This report describes the results of a two-year research project sponsored by the Minnesota Department of Transportation (MnDOT) to develop a portable WIM system that can be readily deployed on local roads. The objective of this project was to develop a portable WIM system that would be used much like a pneumatic tube counter. The developed system is battery operated, low cost, portable, and easily installable on both rigid and flexible pavements. The report includes a sideby- side comparison of data between the developed on-pavement portable WIM system and an in-pavement permanent WIM system.
A majority of intersection-related fatal crashes occur at rural, through/stop intersections. At these intersections, sight restrictions caused by vertical and horizontal curves negatively affect a driver's ability to safely accept a gap in the traffic stream. Static advanced warning signs are sometimes installed at these intersections to warn drivers on the main, through approaches that an intersection is ahead. These warning signs appear to be ineffective. A new Advanced Light-Emitting Diode (LED) Warning System was developed and deployed at a rural, through/stop intersection with limited intersection sight distance due to a severe vertical curve. This warning system actively detects vehicles on all approaches and activates LED blinker warning signs for the conflicting movements. The research project included analysis of driver behavior obtained through video data and a survey of local residents and frequent users of the intersection. This report describes the development, implementation, and evaluation results of this new warning system.
