986 resultados para Road construction contracts.


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In the November 2011 report issued by the Governor’s Transportation 2020 Citizen Advisory Commission (CAC), the commission recommended the Iowa Department of Transportation (DOT), at least annually, convene meetings with the cities and counties to review the operation, maintenance and improvement of Iowa’s public roadway system to identify ways to jointly increase efficiency. In response to this recommendation, Gov. Branstad directed the Iowa DOT to begin this effort immediately with a target of identifying $50 million of efficiency savings that can be captured from the $1.2 billion of Road Use Tax Funds (RUTF) provided to the Iowa DOT, cities and counties to administer, maintain and improve the public roadway system. This would build upon past joint and individual actions that have reduced administrative costs and resulted in increased funding for system improvements. Efficiency actions should be quantified, measured and reported to the public on a regular basis. Beyond the discussion of identifying funding solutions to our road and bridge needs, it is critical that all jurisdictions that own, maintain and improve the nation’s road and bridge systems demonstrate to the public these funds are utilized in the most efficient and effective manner. This requires continual innovation in all aspects of transportation planning, design, construction and maintenance - done in a transparent manner to clearly demonstrate to the public how their funds are being utilized. The Iowa DOT has identified 13 efficiency measures separated into two distinct categories – Program Efficiencies and Partnership Efficiencies. The total value of the efficiency measures is $50 million. Many of the efficiency items will need input, refinement and partnership from cities, counties, other local jurisdictions, and stakeholder interest groups. The Iowa DOT has begun meetings with many of these groups to help identify potential efficiency measures and strategies for moving forward. These partnerships and discussions will continue through implementation of the efficiency measures. Dependent on the measures identified, additional action may be required by the legislature, Iowa Transportation Commission, and/or other bodies to implement the action. In addition, a formal process will be developed to quantify, measure and report the results of actions taken on a regular basis.

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We empirically assess the effect of the winner's curse in auctions for toll road concessions, taking into account, to our knowledge for the first time, problems of commitment and enforcement, using a unique dataset of 49 worldwide road concessions.

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Most counties have bridges that are no longer adequate, and are faced with large capital expenditure for replacement structures of the same size. In this regard, low water stream crossings (LWSCs) can provide an acceptable, low cost alternative to bridges and culverts on low volume and reduced maintenance level roads. In addition to providing a low cost option for stream crossings, LWSCs have been designed to have the additional benefit of streambed stabilization. Considerable information on the current status of LWSCs in Iowa, along with insight of needs for design assistance, was gained from a survey of county engineers that was conducted as part of this research (Appendix A). Copies of responses and analysis are included in Appendix B. This document provides guidelines for the design of LWSCs. There are three common types of LWSCs: unvented ford, vented ford with pipes, and low water bridges. Selection among these depends on stream geometry, discharge, importance of road, and budget availability. To minimize exposure to tort liability, local agencies using low water stream crossings should consider adopting reasonable selection and design criteria and certainly provide adequate warning of these structures to road users. The design recommendations included in this report for LWSCs provide guidelines and suggestions for local agency reference. Several design examples of design calculations are included in Appendix E.

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The Iowa Department of Transportation (DOT) requested a road safety audit (RSA) of the US 59/IA 9 intersection in northwestern Iowa, just south of the Minnesota border, to assess intersection environmental issues and crash history and recommend appropriate mitigation to address the identified safety issues at the intersection. Although the number of crashes at the location has not been significantly higher than the statewide average for similar intersections, the severity of these crashes has been of concern. This RSA was unique in that it included intersection video observation and recorded traffic conflict data analysis, along with the daylight and nighttime field reviews. This report outlines the findings and recommendations of the RSA team for addressing the safety concerns at this intersection.

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In response to local concerns, the Iowa Department of Transportation (DOT) requested a road safety audit (RSA) for the IA Highway 28 corridor through the City of Norwalk in Warren County, Iowa, from the south corporate limits of Norwalk through the IA 5 interchange in Polk County, Iowa. The audit included meeting with City staff to discuss concerns, review crash history and operational issues, observe the route under daylight and nighttime conditions, and analyze available data. This report outlines the findings and recommendations of the audit team for addressing the safety concerns and operational matters along this corridor.

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To date there have been few investigations of the substructures in low-volume road (LVR) bridges. Steel sheet piling has the potential to provide an economical alternative to concrete bridge abutments, but it needs investigation with regard to vertical and lateral load resistance, construction methods, and performance monitoring. The objectives of this project were to develop a design approach for sheet pile bridge abutments for short-span low-volume bridges, formulate an instrumentation and monitoring plan to evaluate performance of sheet pile abutment systems, and understand the cost and construction effort associated with building the sheet pile bridge abutment demonstration project. Three demonstration projects (Boone, Blackhawk, and Tama Counties) were selected for the design, construction, and monitoring of sheet pile abutments bridges. Each site was unique and required site-specific design and instrumentation monitoring. The key findings from this study include the following: (1) sheet pile abutment bridges provide an effective solution for LVR bridges, (2) the measured stresses and deflection were different from the assumed where the differences reflect conservatism in the design and the complex field conditions, and (3) additional research is needed to optimize the design.

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Iowa has about 22,936 bridges on low-volume roads (LVRs). Based on the National Bridge Inventory data, 22 percent of the LVR bridges in Iowa are structurally deficient, while 5 percent of them are functionally obsolete. The substructure components (abutment and foundation elements) are known to be contributing factors for some of these poor ratings. Steel sheet piling was identified as a possible long-term option for LVR bridge substructures; but, due to lack of experience, Iowa needed investigation with regard to vertical and lateral load resistance, construction methods, design methodology, and load test performance. This project was initiated in January 2007 to investigate use of sheet pile abutments. *************Tech Transfer Summary. For full report see: http://publications.iowa.gov/id/eprint/14832*************

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Incentive/disincentive clauses (I/D) are designed to award payments to contractors if they complete work ahead of schedule and to deduct payments if they exceed the completion time. A previously unanswered question is, “Did the costs of the actual work zone impacts that were avoided justify the incentives paid?” This report answers that question affirmatively based on an evaluation of 20 I/D projects in Missouri from 2008 to 2011. Road user costs (RUC) were used to quantify work zone impacts and included travel delays, vehicle operating costs, and crash costs. These were computed using work zone traffic conditions for partial-closure projects and detour volumes and routes for full-closure projects. Conditions during construction were compared to after construction. Crash costs were computed using Highway Safety Manual methodology. Safety Performance Functions produced annual crash frequencies that were translated into crash cost savings. In considering an average project, the percentage of RUC savings was around 13% of the total contract amount, or $444,389 of $3,464,620. The net RUC savings produced was around $7.2 million after subtracting the approximately $1.7 million paid in incentives. In other words, for every dollar paid in incentives, approximately 5.3 dollars of RUC savings resulted. I/D provisions were very successful in saving RUC for projects with full-closure, projects in urban areas, and emergency projects. Rural, non-emergency projects successfully saved RUC but not at the same level as other projects. The I/D contracts were also compared to all Missouri Department of Transportation contracts for the same time period. The results show that I/D projects had a higher on-time completion percentage and a higher number of bids per call than average projects. But I/D projects resulted in 4.52% higher deviation from programmed costs and possibly more changes made after the award. A survey of state transportation departments and contractors showed that both agreed to the same issues that affect the success of I/D contracts. Legal analysis suggests that liquidated damages is preferred to disincentives, since enforceability of disincentives may be an issue. Overall, in terms of work zone impact mitigation, I/D contracts are very effective at a relatively low cost.

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This is a story about a highway project near the small town of Wever, Iowa, and an American Indian village that existed at the location prior to the Europeans' arrival. The culture that lived in this village existed in a 10 state region of the Upper Midwest and may have been the ancestors of tribes living in the Midwest when European explorers entered the region. An archaeological recovery of information from the site was undertaken by the Iowa Department of Transportation because four-lane construction of U.S. 61 could not be accomplished without destroying most of the site. This site proved to be one of the richest archaeological finds in the State of Iowa. ǂc Iowa Department of Transportation.

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Iowa's secondary road network contains nearly 15,000 bridges which are less than 12 m (40 ft) long. Many of these bridges were built several decades ago and need to be replaced. Box culvert construction has proven to be an adequate bridge replacement technique. An alternative to box culverts is the Air-O-Form method of arch culvert construction. The Air-O-Form method has several potential advantages over box culvert construction. The new technique uses inflated balloons as the interior form in the construction of an arch culvert. Concrete is then shotcreted onto the balloon form to complete the arch culvert. The objective of the research project was to construct an air formed arch culvert to determine its applicability as an alternative county bridge replacement technique. The project had the following results: (1) The Air-O-Form method can be used to construct a structurally sound arch culvert; and (2) The method must become more economical if it is to compete with box culverts.

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Iowa's public road system of 112,000 miles is one of the largest and the best in the nation. It represents a considerable financial investment of taxpayer revenues over the years. And, it requires a sustained investment to preserve an economical level of transport service into the future. In 1982, a Governor's Blue Ribbon Transportation Task Force evaluated the effectiveness of Iowa's entire transportation system. Four important Task Force recommendations dealt with public road administrative issues in Iowa. These issues were related to: (1) Design criteria and levels of maintenance; (2) Consistency in the use of standards among jurisdictions; (3) Consolidation of maintenance operations at one jurisdiction level; and (4) Jurisdicational authority for roads; The issues formed the background for Research Project HR-265.

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A 5.8 mile section of Dubuque County (Iowa) Road D-53 was selected for this project, the objective of which were to: 1. identify a cost effective asphalt emulsion bound macadam typical cross section; 2. determine the effectiveness of engineering fabric placed under macadam roadbeds; and 3. evalaute the use of emulsions in surface seal coats. A number of conclusions were reached: 1. The minus #200 sieve material for the macadam stone should be held to a minimum. For the emulsion used on this project, the minus #200 material had less than 4 percent to achieve satisfactory coating of the macadam stone. 2. The placement of the emulsion treated macadam required no additional equipment or time than the plain macadam placement. 3. Emulsion treating the macadam stone for the shoulder base appears unnecessary. 4. The emulsion treated macadam base beneath an asphaltic concrete wearing surface yielded a higher structural rating than the plain macadam beneath a comparable ashaltic concrete surface. 5. The performance of the fabric between the subgrade and the macadam base to prevent soil intrusion into the base could not be determined by the non-destructive testing conducted. 6. When no choke stone is used over the macadam base, allowance for ac mix overrun should be made. 7. Use of an emulsion instead of a cutback asphalt saved money and energy. However, the poor performance of the seal coat negated any real savings.

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In an earlier research project, HR-204, the magnitude and nature of highway related tort claims against counties in Iowa were investigated. However, virtually all of the claims identified in that research resulted from incidents that occurred in areas with predominantly agricultural land use. With recent increases in the rural non-farm population, many traditionally urban problems are also appearing in built-up areas under county jurisdiction. This trend is expected to continue so that counties must anticipate a change in the nature of the tort claims they will encounter. Problems that heretofore have been unique to cities may become commonplace in areas for which counties are responsible. The research reported here has been directed toward an investigation of those problems in rural subdivisions that lead to claims growing out of the provision of highway services by counties. Lacking a sufficient database among counties for the types of tort claims of interest in this research, a survey was sent to 259 cities in Iowa in order to identify highway related problems leading to those claims. The survey covered claims during a five year period from 1975 to 1980. Over one-third of the claims reported were based on alleged street defects. Another 34 percent of the claims contained allegations of damages due to backup of sanitary sewers or defects in sidewalks. By expanding the sample from the 164 cities that responded to the survey, it was estimated that a total of $49,000,000 in claims had been submitted to all 259 cities. Over 34% of this amount resulted from alleged defects in the use of traffic signs, signals, and markings. Another 42% arose from claims of defects in streets and sidewalks. Payments in settlement of claims were about 13.4% of the amount asked for those claims closed during the period covered by the survey. About $9,000,000 in claims was pending on June 30, 1980 according to the information furnished. Officials from 23 cities were interviewed to provide information on measures to overcome the problems leading to tort claims. On the basis of this information, actions have been proposed that can be undertaken by counties to reduce the potential for highway-related claims resulting from their responsibilities in rural subdivisions and unincorporated communities. Suggested actions include the eight recommendations contained in the final report for the previous research under HR-204. In addition, six recommendations resulted from this research, as follows: 1. Counties should adopt county subdivision ordinances. 2. A reasonable policy concerning sidewalks should be adopted. 3. Counties should establish and implement a system for setting road maintenance priorities. 4. Counties should establish and implement a procedure for controlling construction or maintenance activities within the highway right of way. 5. Counties should establish and implement a system to record complaints that are received relating to highway maintenance and to assure timely correction of defective conditions leading to such complaints. 6. Counties should establish and implement a procedure to ensure timely advice of highway defects for which notice is not otherwise received.

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"Metric Training For The Highway Industry", HR-376 was designed to produce training materials for the various divisions of the Iowa DOT, local government and the highway construction industry. The project materials were to be used to introduce the highway industry in Iowa to metric measurements in their daily activities. Five modules were developed and used in training over 1,000 DOT, county, city, consultant and contractor staff in the use of metric measurements. The training modules developed deal with the planning through operation areas of highway transportation. The materials and selection of modules were developed with the aid of an advisory personnel from the highway industry. Each module is design as a four hour block of instruction and a stand along module for specific types of personnel. Each module is subdivided into four chapters with chapter one and four covering general topics common to all subjects. Chapters two and three are aimed at hands on experience for a specific group and subject. This module includes: Module 3 - Road and Bridge Design. This module provides hands on examples of how to use metric measurements in the design of roads and structures.

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In today's era of advanced methods, it is interesting that a centuries-old Roman road-building concept can be the most attractive alternative available. The need for a less expensive road base construction method is very apparent, especially to the county engineer faced with maintaining quality lower traffic volume farm-to-market roads. The revival of the Macadam stone base is one possible solution. Des Moines County believed a Macadam road had excellent possibilities for their particular needs. They proposed a research project designed to eliminate some of the unknown factors of Macadam stone base construction. It is the intent of this research project to develop standardized design procedures and serve as an aid for others in constructing a Macadam base roadway. The Iowa Department of Transportation has published special provisions for the construction of Macadam stone bases that were adopted as the guideline specifications for the research project.