Search Content

These are the Appendices for report number MN/RC - 1999-24: An Evaluation of the Cambridge Telework Center.

This report describes a long-term study to monitor and evaluate the ecosystem recovery of seven wetland restorations in south central Minnesota. The study looks at the impact of planting on wetland restoration success in inland wetlands and develops a methodology to assess wetland restoration success. The study focused on the following question: To what extent can revegetation stimulate overall biological recovery in isolated restoration sites? Researchers used aspects of ecosystem function and structure to characterize recovery rates in planted and unplanted restored sites relative to one another and to reference wetlands, as well as indices of biotic integrity for plants, invertebrates, birds, and amphibians in addition to other indicators of ecosystem structure, such as soil organic matter and water chemistry. Researchers developed field protocols, created biotic indices, and established baseline monitoring on each site including an as-built topographic survey, installation of groundwater and surface water stations, characterization of soils, vegetation, and vertebrates. A long-term monitoring system is now in place that will allow for the assessment of ecosystem recovery of seven restored wetlands relative to four reference wetlands.

This research looks at bicycle transportation, particularly bicycle commuting, in three North American cities with extensive bicycling activity and programs: Madison, Wisconsin; Boulder, Colorado; and Toronto, Ontario, Canada. The study describes bicycle transportation in these cities to gain ideas for further improvements in Minnesota bicycle transportation. Madison, Boulder, and Toronto share a reputation for high levels of bicycling activity. Each city plans for additions to its extensive system of bike paths and bike lanes. Wisconsin's state plan calls for an interconnected transportation system across government boundaries and jurisdictions and completed a Wisconsin Bicycle Transportation Plan in 1998. Boulder completed a Bicycle System Plan in 1996 as part of its Transportation Master Plan Update for the Boulder Valley. It, too, addresses the need to develop a continuous and well-connected provincial government of Ontario recently amalgamated the six municipal governments in the Toronto metro area to form The New City of Toronto, and the new city is now working on a new bicycle plan. A City Cycling Committee, a committee of the city council, looks at programs to increase the quantity and quality of bicycle trips in Toronto. The three cities also have developed public initiatives to promote bicycling, including bike-to-work events, free bike programs, and awards programs. All three cities publish extensive information about bicycling programs and issues on the Internet. Internet sites include official city sites, sites managed by independent organizations and individual bike activists, and electronic newsletters.

This Phase II study involved studying the short-term and long-term effects of the Compliance Review (CR) programs conducted in the Region 5 states of Wisconsin, Indiana, Michigan, Minnesota, Ohio, and Illinois on the Out-of-Service (OOS) rates of interstate freight-carriers based in those states. A preliminary analysis of the inspections data revealed low OSS rates based on inspection records--across all level of inspection--for the years 1993-94, indicating defective collection/interpretation of data and thereby invalidating any OOS rate analysis for this time period. Also, it was found that Level 1 and 2 inspections together constitute nearly 80 percent of all inspections records, thus marginalizing the effect of the other levels of inspection on the final results of this analysis. The results of both the short-term and long-term effects of OOS rate analysis suggest an overall positive effect of the Compliance Review program on the reduction of OOS (Event and Violation) rates of the carriers. These results are consistent over the rest of the time period (1995-97) and across three levels of inspection (Levels 1, 2, and 3). The conclusions drawn about the nature of the effects of a Compliance Review could be much better validated if the currently spurious inspections data for the years 1993-94 were restored, or a fresh analysis using later available data (1997-99) were carried out based on the same algorithms.

Traffic centers gather information from traffic sensors at regular intervals, but storing the data for future analysis becomes an issue. This report details work to improve the speed and effectiveness of traffic databases. In this project phase, researchers redesigned the data model based on the previous phase's data model and decreased the storage requirements by one-third. Researchers developed a web-based Graphical User Interface (GUI) for users to specify the query of interest; the outcome of the performance tuning gave users reasonable response time. The beneficiaries of this effective database would include the driving public, traffic engineers, and researchers, who are generally not familiar with the query language used in the database management system. This report summarizes the detailed reference, such as benchmark query, sample data, table schema, conversion code, and other information.

Current research focuses on advancing the existing capabilities for stability analysis of pile foundations. To this end, researchers developed a continuum model and a structural model. In the continuum model, three-dimensional solid finite elements and mapped infinite elements are employed for modeling the three-dimensional geometry, pile-soil-pile interaction, and unbounded domain whereas three dimensional thin-layer interface elements are used for modeling interaction behavior between the pile and the soil. In contrast, thin-walled structural elements and flat shell elements are used for the piles and pile cap in the structural model. Nonlinear soil springs are adopted for modeling the lateral and axial pile-soil interaction. The continuum model is capable of accounting for pile-soil interaction and pile-soil-pile interaction appropriately whereas the structural model is efficient and simple to implement. To include pile-soil-pile interaction for groups of closely spaced piles, the group-reduction factor is introduced in an approximate fashion in the structural model. Both the continuum model and structural model developed in the current study are used together for some representative but simpler pile configurations to obtain the group-reduction factor.

The annual Congestion Study is a geographical illustration of the metropolitan freeway system's traffic performance. It portrays time and areas of congested traffic flow during the A.M. and P .M. peak periods. Congested areas are determined from data gathered by traffic management sensor arrays. The data, five-minute volumes and lane occupancy values, provide input into the determination of the average five-minute running speeds per lane. This report is a summary of the time a freeway operates below 45 miles per hour. Freeway system field observations indicate that under this condition, shock waves develop in the traffic flow. Our working definition of congestion is then traffic flow below 45 miles per hour. The data summary compares the traffic during the month of October in each of the years. This is done to minimize the effects of construction and maintenance-induced congestion and to account for school-induced traffic loads. The study uses 1993 as a base year, the first year the report was done.

This report documents the research that incorporated reliability analysis into the existing mechanistic-empirical (M-E) flexible pavement design method for Minnesota. Reliability in pavement design increases the probability that a pavement structure will perform as intended for the duration of its design life. The report includes a comprehensive literature review of the state-of-the-art research. The Minnesota Road Research Project (Mn/ROAD) served as the primary source of data, in addition to the literature review. This research quantified the variability of each pavement design input and developed a rational method of incorporating reliability analysis into the M-E procedure through Monte Carlo simulation. Researchers adapted the existing computer program, ROADENT, to allow the designer to perform reliability analysis for fatigue and rutting. A sensitivity analysis, using ROADENT, identified the input parameters with the greatest influence on design reliability. Comparison designs were performed to check ROADENT against the 1993 AASHTO guide and the existing Minnesota granular equivalency methods. Those comparisons showed that ROADENT produced very similar design values for rutting. However, data suggests that the fatigue performance equation will require further modification to accurately predict fatigue reliability.

This Technical Summary pertains to Report 2023-19, “Cost Estimate of B vs. C Grade Asphalt Binders,” published May 2023.

This report presents results from a laboratory study and field implementation of acoustic emission monitoring of fatigue cracks in cover-plated steel bridge girders. The acoustic monitoring successfully detected growing fatigue cracks in the lab when using both source location and a state of stress criteria. Application of this methodology on three field bridges also proved successful by detecting a propagating crack in two of the bridges and an extinguished crack in a third bridge. Researchers tested a double angle retrofit, designed by the Minnesota Department of Transportation, both in the lab and in the field of girder with fatigue cracks in the top flange. This retrofit does not require removal of concrete deck, and only involves bolting the retrofit to the bridge girder web. The double angle retrofit applied to laboratory test girder resulted in a reduction of flange stresses by 42 percent. Field implementation of the retrofit had mixed success. On one bridge, stress ranges in the cracked flange was reduced by 43 percent. However, on a second test bridge, the reduction was only 8 percent, likely due to the inadequate space for proper installation of the retrofit.