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Spring is a critical period for Minnesota's roads because the roadbed soils and aggregate base materials are in a weakened state during and after the thawing process. Spring load restrictions (SLR) are used as a preservation strategy to reduce damage, thereby protecting Minnesota's investment in the infrastructure. However, the imposition of spring load restrictions impacts industry, both in their operations, and financially. While it is clear that spring load restrictions benefit the infrastructure, there are two issues of which little is known: (1) the economic impacts that result when access to the transportation system is restricted and (2) extent of enforcement efforts. The development of the Spring Load Restrictions Task Force was in response to 1999 legislation requiring the Commissioner of Transportation to establish a task force to study spring load restrictions and report to the legislature its findings and any recommendations for legislative action by February 1, 2000. The legislation also calls for task force members that represent many interests including aggregate and readymix producers, agriculture, waste haulers, construction, and logging. Other members representing local agencies, associations, and enforcement have also been included. The task force objectives were to study the current status of spring load restrictions in the state of Minnesota, explore the economic impacts of the load restrictions, and report the findings to the legislature.

High quality aggregates for highway construction are in short supply in many parts of Minnesota. Although the current total supply is adequate, the distribution of sources results in localized shortages. In some areas, it is necessary to import high-quality aggregates from distant locations. Long haul distances can increase aggregate prices substantially, add significantly to the overall project cost, and require the expenditure of sizable amounts of energy. One available source of high-quality aggregate is existing portland cement concrete pavement currently in need of reconstruction. Re-using this aggregate would conserve natural resources, result in cost savings in areas experiencing aggregate shortages and conserve natural resources, result in cost savings in areas experiencing aggregate shortages, and conserve energy in the form off fuel savings when aggregates must be acquired from distant sources. A research study was undertaken to; Determine the feasibility of recycling portland cement concrete pavement; evaluate the new recycled pavement; determine the cost effectiveness of recycling versus conventional paving; and determine the amount of energy consumed and natural resources conserved. Economic and engineering factors led to the selection of a 16-mil (25.7 km.) segment of U.S. 59 from Worthington to Fulda in Southwestern Minnesota for :his study. The in place roadway which was constructed in 1955 and consisted of a 9-7-9 inch (23-18-23 cm.) thick, 24 foot (7.3 m) wide, non-reinforced "D"-cracked concrete pavement with soil shoulders was broken, salvaged, and crushed. Material passing the #4 sieve (0.187 in., 0.476 cm) was used for base stabilization and shoulder aggregate, and material retained on the #4 sieve but passing the 3/4 in. (1.905 cm) sieve was used] as the coarse aggregate for concrete paving. Pavement removal began May 15, 1980 and concrete paving was completed September 24. 1980.

This document serves as a guide for the potential future design and deployment of an integrated Intelligent Transportation System along TH 7 from Hutchinson to the Twin Cities in Minnesota. The document presents a conceptual plan including a strategy for ITS deployment as recommended by the TH 7 Technical Committee. The concept study was performed to identify opportunities to apply advanced technology to address unresolved problems and needs from proposed physical roadway improvements scheduled along TH 7 over the next several years. A key goal of this study was to identify advanced technology that could cooperatively be applied to enhance transportation management and traveler information capabilities in order to increase safety and efficiency of the transportation system along the TH 7 Corridor.

The Trilogy project was an Intelligent Transportation System (FTS) demonstration of the broadcast\ of freeway system traveler information to both commercial and commuter drivers over a 25-mile (40.3 km) radius of the Twin Cities Metropolitan Area. In this project, real-time freeway system operating conditions, particularly incidents and traffic congestion, were monitored at the Minnesota Department of Transportation (Mn/DOT) Traffic Management Center (TMC). This information was broadcast to a fleet of test vehicles with dashboard mounted display screens. Two different systems were used to broadcast traveler information. The first system, Dynaguide 2.0, utilized the Radio Broadcast Data System (RBDS) - Traffic Message Channel; and the second system, Dynaguide 3.0, utilized the Seiko High Speed Data System (HSDS) to transmit messages to in-vehicle receivers. Dynaguide 2.0 provided the user with information on incidents, planned events, and traffic congestion via icons and text messages generated by operators at the TMC. In comparison, Dynaguide 3.0 provided real-time color coded freeway link speed data and ramp metering conditions generated from the traffic management system detection sensors in addition to the information generated by the TMC operators. Both devices also had the capability to display traffic condition test messages.

This summary report is an illustrated description of a surface condition rating procedure for flexible pavements. A slide tape presentation has also been prepared on this subject. This report and the slide tape can be used together to supplement each other and the report can be used as a reference during field condition surveys. Both documents are intended to be training aids for people who are responsible for evaluating pavement conditions and selecting appropriate maintenance procedure

The objective of this study is to evaluate the effectiveness of various sealers for use on concrete bridge decks. The bridge deck selected for this project carries I-35E over Jefferson Avenue in St. Paul. The bridge was built in 1974 and overlaid with low slump dense concrete in 1983. It was first opened to traffic in November 1984. Traffic volume is 6600 ADT with no heavy commercial traffic.

The purpose of this three month study has been to determine whether it is feasible to simulate an asphalt pavement section using the elastic theory. This has been done by first obtaining samples from Investigation 183, Test Section 102 and determining the stress-strain properties of the various layers using the repeated load triaxial test under various conditions. Appropriate moduli have then been put. into an elastic layered system which is used to calculate stresses and strains within the system. The Benkelman beam deflections measured in the field have been simulated in this manner and the comparison between computed and measured deflections is used to show whether the elastic theory simulates a flexible pavement. The possibility of determining equivalencies between stabilized base courses and granular base courses are explored as are the use of other parameters for design purposes.

In 1998, the Minnesota Department of Transportation (Mn/DOT) conducted a project originally named Metro Computer Aided Dispatch/Automatic Vehicle Location (CAD/AVL) project. It was than changed to what it is known today - Safety with Automated Intelligent Locator (SAIL). The purpose of this project was to test CAD software and AVL technology in the Twin Cites metro area. This was an operational test that ran from March 19, 1999 to February 26, 2000. Six maintenance vehicles were equipped with portable mobile data terminals (MDT) for the test. The test, at that time, was used to determine the feasibility of AVL technology for maintenance activities in the metro area. The benefits of this project were real-time information for improving decision-making, recording information for after storm playback and analysis, reducing paper work, allowing operator to respond and send messages when it is safe, and provide information for verification of route completion. The SAIL 2 project is an extension of SAIL 1 to further assess the application of AVL systems for gaining value in overall snow fighting techniques, decision support systems, and area-wide highway maintenance issues for winter and summer operations by deployment of fully functional AVL systems. AVL systems were installed on 60 snow removal/highway maintenance vehicles within several Mn/DOT districts in the State of Minnesota. The project is unique from other AVL projects because of the design and planning for integration with Mn/DOT's existing resource management systems.

The Northstar Workshop, "A Bold New Look at Minnesota's Roads and Loads," was held at the Leamington Hotel, Minneapolis, Minnesota on November 13, 14, and 15, 1984. The Workshop addressed two main aspects of highway loads - the 80,000-lb. gross truck load and the springtime load limitation policies. There was an attendance of about 140, mainly from Mn/DOT, but also from the four adjacent states and Michigan, the two bordering Canadian provinces, the Minnesota State Planning Agency and Legislative Research, agencies such as AASHTO and FHWA, the Minnesota Motor Transport Association, county and city engineers, and the paving industry and truck manufacturing industry; thus, it constituted a comprehensive cross-section of persons concerned with the subjects under discussion. The format of the Workshop was one and one-half days of presentation of papers by individuals on subjects which had been assigned to them, with limited questions and discussion after each one, followed by group discussions for which the attendees were divided into six groups. Reports of these discussions were made to the full conference by group leaders and a final summary was made by Deputy Commissioner Robert McDonald. Following the Workshop, Mr. McDonald appointed a Truck Weight Action Group to compile recommendations based on the papers and discussions at the Workshop, and this group has made its report; its recommendations, in effect, represent a summary of the dominant thoughts of the Workshop. The report is included in Appendix A of the proceedings.

The Minnesota Department of Transportation has collected pavement distress and ride data from the pavements in their system since 1967. In 1986, the data was analyzed to develop pavement performance prediction models that were based on the growth of pavement distresses such as cracking, rutting, and roughness. The analysis at that time was limited by the amount of data available and was considered to be an interim study. The amount and quality of data presently available has improved from that available in 1986 and new or improved models could be developed. The work involved the analysis of all of the pavement condition data collected since 1983 when improved collection procedures were implemented. A literature search was also conducted. The results of the study was the evaluation of pavement life and the development of mathematical models that describe the growth of the distresses rated and the change in roughness over time. Over 100 pavement groupings were evaluated. The groupings were selected on the bases of a variety of pavement attributes including surface type, functional class, and region (construction district). The life of the pavements were evaluated based on the number of years they remained in service and on the basis of performance indices. It was found that the number of years a pavement remains in service can not be used to infer performance potential since a number of pavements were rehabilitated for reasons other than condition; the predicted pavement condition provides a better indication of the performance life of a pavement. The prediction of future pavement performance is accomplished by using the distress growth models to predict the growth of the distresses; the future condition indices are than calculated from the predicted distress amounts.