The main focus of this collaborative project was to truly understand, organize and create a spatial database for the all unincorporated communities in the State of Minnesota. An “unincorporated community” means a geographic area having a common social identity without municipal organization or official political designation.
The main purpose of this investigation was to determine the amount of degradation that occurs during construction of granular bases and the amount which takes place while in service under a bituminous surface. A second objective was to determine which laboratory tests could be used to identify the materials which would degrade the most.
Six granular base projects were selected for testing. Six different aggregates were tested and results analyzed for degradation. Assessment of degradation was based on changes in the percent passing the No. 200 sieve of samples taken as produced, after compaction and after being placed in service.
Some of the more important findings and conclusions of this study are:
1. Some degradation was noted on all six projects, occurring both during compaction and under traffic.
2. None of the laboratory tests conducted were found to be suitable for indicating aggregates which degrade the most.
This report is the first of several volumes prepared for the Minnesota Local Road Research Board (LRRB) which contain summaries of highway research projects which have been conducted in Minnesota. These summaries will be valuable references to City and County Engineers and others who are responsible for the construction and management of roads, streets, highways and other related facilities. Volume I summarizes over 50 research projects which have been sponsored wholly or in part by the Minnesota LRRB since 1959. These projects cover a wide variety of subjects including geometric standards, pavement design and evaluation, materials evaluation, and roadside turf establishment to name a few. Much of the information resulting from these projects is of value to all city and county engineers, as well as Mn/DOT engineers and the industry.
The Minnesota Department of Transportation (Mn/DOT) research report is the key document for a researcher to present research results, transfer knowledge to users, and encourage possibilities to implement research. If these aims are to be achieved, it is important for report authors to produce a well-organized and clearly-written document. The Mn/DOT Office of Research Administration (ORA) has developed this document, General Guidelines for the Publication of Research Reports, to aid the author in writing and constructing the research report. Following the guidelines will also ensure the quality and consistency of presentation in all Mn/DOT research reports.
The Minnesota Interstate Truck Parking Study was undertaken to help Mn/DOT develop the information necessary to support decisions regarding future approaches to the truck parking issues in Minnesota. The issues examined by the study effort include determining what the state's role should be in the provision of truck parking; which provisions of long term truck parking will provide the greatest support to the state's economy, and what actions will provide the greatest impact on traffic safety, while taking maximum advantage of effective technology and available federal programs.
The Minnesota Interstate Truck Parking Study examined the supply and demand of public and private commercial vehicle parking along Minnesota’s three primary interstate corridors: I-90, I-35, and I-94. The study was conducted through three primary tasks: 1) An inventory of Minnesota's Interstate Truck Parking Supply; 2) Truck Parking Demand Analysis; 3) Survey Results of Trucking Company Practices and Attitudes Regarding Truck Parking.
Mn/Model is a project that combines landscape and archaeological databases in a Geographic Information System (GIS) with statistical prediction methods to provide an estimate of the risk that a given location contains archaeological artifacts. Planners use these estimates both to seek out areas of low risk and to accommodate areas of high risk when planning transportation projects. Obviously, more accurate risk estimates lead to improved planning and reduced costs.
Mn/Model is about to move into its fourth phase, which will include improved landscape and archaeological data. At this time, Mn/DOT wishes to reconsider the statistical prediction methods used in Phase 3 to determine if better alternatives are available.
This project proposed and compared eight prediction methods, the Phase 3 method and seven alternatives. The methods were logistic regression with BIC model selection (the Phase 3 approach), logistic regression with Bayesian model averaging, naïve Bayes classification, tree-structured regression, "bumped" trees, "bagged" trees, "double bagged" trees, and "boosted" trees. Bumping, bagging, and boosting are examples of "perturb and aggregate methods," which repeatedly modify the data in minor ways and then combine the predictions from the modified data sets. Overall, bagging, double bagging, and boosting had the best predictive ability.
We recommend that bagged trees, or bagging, be the default prediction method for Phase 4. Bagging is easier to do in S-Plus (the statistical software used) than boosting and easier to implement in the GIS framework. Bagging provides substantial improvement in predictive capability over the Phase 3 method. Tree-structured models are also fairly easy to explain to the general public. Double bagging provides a small improvement over bagging, but at the cost of substantially more effort in implementation.
Motor carriers face a number of regulations in carrying on their business. Trucks are typically regulated as to their length, width, height, load (in terms of gross vehicle weight), and axle weight. The purpose of these regulations is to promote public safety and protect the quality of road surfaces. Highway regulations affecting motor carriers are primarily a state-level responsibility in the United States. Minnesota has its own set of truck size and weight regulations as do neighboring states and Canadian provinces. Because states set their own regulations on truck size and weight, the commercial trucking industry measures the appropriateness of Minnesota regulations to a large extent based on their congruence with those in adjacent states. The object of this study is to determine the extent to which major shippers, the clients of commercial motor carriers, feel constrained by truck size and weight regulations in Minnesota and whether their needs are being met.
The purpose of this project was to test the feasibility of the integration of heterogeneous sensor systems at the implementation level, as well as to investigate the theoretical development of the algorithms to integrate the navigation information. The goal is a set of algorithms to handle failures in any particular sensor and adaptive adjustment of parameters and navigational fixes. Using real field data, we have demonstrated that different sensors can be integrated in a low cost system. We have also demonstrated that no single sensor can handle the arbitrary situation, but that multiple sensors yields redundancy and robustness unachievable by each sensor alone.
Highway engineers are expected by the public to maintain continuously adequate roads, while the highway authorities expect a prudent use of available funds (Bulman and Weatherall, 1990). It is common and advisable to do a cost analysis of various road surfacing materials when considering major construction on a particular stretch of roadway. Generally, such analysis would include costs to the agency or firm conducting the work, such as the cost of the initial construction, detour cots, and maintenance costs during the estimated lifetime of the project. However, such an analysis would yield results that more accurately reflect the costs and benefits to society if costs borne primarily by the public could be included in the decision-making framework. These costs are proper to include for a government agency, whose ultimate function is to serve the public. The purpose of this paper is to provide explanations and rationales for an accompanying computer program, which models costs of alternative road surfacing materials over the lifetime of a stretch of road. A quick reference guide to the worksheets and an example of the calculations involved are included as appendices. This document is intended to be used as a guide. Some cost functions may be deleted if appropriate. It has been prepared in conjunction with Graig Gilbertson, an engineer with the Minnesota Department of Transportation, and is intended for use in analyzing public roads.
This report describes the development of a data-driven methodology for estimating the mean daily traffic (MDT) for different vehicle classes from short classification-count samples. Implementation of the methodology requires that an agency maintain a small number of permanent classification counters (PCC), whose output is used to estimate parameters describing their monthly and day-of-week variation patterns and covariance characteristics. The probability of a match between a short classification count sample and each of the PCCs is computed, as well as the estimates of the short-counts site's MDTs which would arise if the short-count site had variation patterns identical to each of the PCCs. The final MDT estimates are then simply the weighted averages of these component MDTs, with the matching probabilities providing the weights.
Empirical evaluation of the methods using data collected at the Long Term Pavement Performance Project sites in Minnesota indicated that a reliable match of a short-count site could be made using a sample consisting of a one-day classification count from each month of the year. An evaluation of two-day classification count samples indicated that a two-day count is not sufficient to reliably match the site to a factor group, justifying estimation of MDT using weighted averages. For estimating combination vehicle MDT, these samples should be taken between May and October, and between Tuesday and Thursday. In this case the estimated MDT differed on average by about 10% - 12% compared to estimates based on full year's worth of counts, and differed by less than 26%, 95% of the time.
