996 resultados para road transportation
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This document describes planned investments in Iowa’s multimodal transportation system including aviation, transit, railroads, trails, and highways. A large part of funding available for highway programming comes from the federal government. Accurately estimating future federal funding levels is dependent on having a multiyear federal transportation authorization bill in place and having a sustainable and solvent federal Highway Trust Fund. The most recent federal authorization, Moving Ahead for Progress in the 21st Century (MAP-21), will expire September 30, 2014. At the same time that MAP-21 expires and absent Congressional action, the federal Highway Trust Fund will no longer be able provide funding at current levels resulting in up to a 90 percent reduction in federal highway funding for federal fiscal year 2015. These two issues provide funding uncertainty with this program in fiscal years 2015 and beyond.
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The Federal Highway Administration (FHWA) estimates that 58 percent of roadway fatalities are lane departures, while 40 percent of fatalities are single-vehicle run-off-road (SVROR) crashes. Addressing lane-departure crashes is therefore a priority for national, state, and local roadway agencies. Horizontal curves are of particular interest because they have been correlated with increased crash occurrence. This toolbox was developed to assist agencies address crashes at rural curves. The main objective of this toolbox is to summarize the effectiveness of various known curve countermeasures. While education, enforcement, and policy countermeasures should also be considered, they were not included given the toolbox focuses on roadway-based countermeasures. Furthermore, the toolbox is geared toward rural two-lane curves. The research team identified countermeasures based on their own research, through a survey of the literature, and through discussions with other professionals. Coverage of curve countermeasures in this toolbox is not necessarily comprehensive. For each countermeasure covered, this toolbox includes the following information: description, application, effectiveness, advantages, and disadvantages.
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The objective of this project was to evaluate the in-use fuel economy and emission differences between hybrid-electric and conventional transit buses for the Ames, Iowa transit authority, CyRide. These CyRide buses were deployed in the fall of 2010. Fuel economy was compared for the hybrid and control buses. Several older bus types were also available and were included in the analysis. Hybrid buses had the highest fuel economy for all time periods for all bus types. Hybrid buses had a fuel economy that was 11.8 percent higher than control buses overall, 12.2 percent higher than buses with model years 2007 and newer, 23.4 percent higher than model years 2004 through 2006, 10.2 percent higher than model years 1998 through 2003, 38.1 percent higher than model years 1994 through 1997, 36.8 percent higher than model years 1991 through 1993, and 36.8 percent higher for model years pre-1991. On-road emissions were also compared for three of the hybrid buses and two control buses using a portable emissions monitor. On-average, carbon dioxide, carbon monoxide, and hybrid carbon emissions were much higher for the control buses than for the hybrid buses. However, on average nitrogen oxide emissions were higher for the hybrid buses.
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Excessive daytime sleepiness underpins a large number of the reported motor vehicle crashes. Fair and accurate field measures are needed to identify at-risk drivers who have been identified as potentially driving in a sleep deprived state on the basis of erratic driving behavior. The purpose of this research study was to evaluate a set of cognitive tests that can assist Motor Vehicle Enforcement Officers on duty in identifying drivers who may be engaged in sleep impaired driving. Currently no gold standard test exists to judge sleepiness in the field. Previous research has shown that Psychomotor Vigilance Task (PVT) is sensitive to sleep deprivation. The first goal of the current study was to evaluate whether computerized tests of attention and memory, more brief than PVT, would be as sensitive to sleepiness effects. The second goal of the study was to evaluate whether objective and subjective indices of acute and cumulative sleepiness predicted cognitive performance. Findings showed that sleepiness effects were detected in three out of six tasks. Furthermore, PVT was the only task that showed a consistent slowing of both ‘best’, i.e. minimum, and ‘typical’ responses, median RT due to sleepiness. However, PVT failed to show significant associations with objective measures of sleep deprivation (number of hours awake). The findings indicate that sleepiness tests in the field have significant limitations. The findings clearly show that it will not be possible to set absolute performance thresholds to identify sleep-impaired drivers based on cognitive performance on any test. Cooperation with industry to adjust work and rest cycles, and incentives to comply with those regulations will be critical components of a broad policy to prevent sleepy truck drivers from getting on the road.
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Report on the Iowa Department of Transportation for the year ended June 30, 2012
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Weekly letting report.
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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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The Institute for Transportation (InTrans) at Iowa State University completed work on an in-depth study of crash history on lowvolume, rural roads in Iowa in December 2010. Results indicated that unpaved roads with traffic volumes greater than 100 vehicles per day (vpd) exhibit significantly higher crash frequencies, rates, and densities than any other class of low-volume road examined, paved or unpaved. The total mileage for this class of roadway in Iowa is only about 4,400 miles, spread over 99 counties in the state, which is certainly a manageable number of miles for individual rural agencies. The purpose of this study was to identify and examine several unpaved, local road segments with higher than average crash frequencies, select and undertake potentially-beneficial mitigation, and evaluate the results as time allowed. A variety of low-cost options were considered, including engineering improvements, enhanced efforts by law enforcement, and educational initiatives. Using input, active support, and participation from local agencies and state and Federal safety advocates, the study afforded a unique opportunity to examine useful tools for local rural agencies to utilize in addressing safety on this particular type of roadway.
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The Institute for Transportation (InTrans) at Iowa State University completed work on an in-depth study of crash history on lowvolume, rural roads in Iowa in December 2010. Results indicated that unpaved roads with traffic volumes greater than 100 vehicles per day (vpd) exhibit significantly higher crash frequencies, rates, and densities than any other class of low-volume road examined, paved or unpaved. The total mileage for this class of roadway in Iowa is only about 4,400 miles, spread over 99 counties in the state, which is certainly a manageable number of miles for individual rural agencies. The purpose of this study was to identify and examine several unpaved, local road segments with higher than average crash frequencies, select and undertake potentially-beneficial mitigation, and evaluate the results as time allowed. A variety of low-cost options were considered, including engineering improvements, enhanced efforts by law enforcement, and educational initiatives. Using input, active support, and participation from local agencies and state and Federal safety advocates, the study afforded a unique opportunity to examine useful tools for local rural agencies to utilize in addressing safety on this particular type of roadway.
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"Technical challenges exist with infrastructure that can be addressed by nondestructive evaluation (NDE) methods, such as detecting corrosion damage to reinforcing steel that anchor concrete bridge railings to bridge road decks. Moisture and chloride ions reach the anchors along the cold joint between the rails and deck, causing corrosion that weakens the anchors and ultimately the barriers. The Center for Nondestructive Evaluation at Iowa State University has experience in development of measurement techniques and new sensors using a variety of interrogating energies. This research evaluated feasibility of three technologies — x-ray radiation, ground-penetrating radar (GPR), and magnetic flux leakage (MFL) — for detection and quantification of corrosion of embedded reinforcing steel. Controlled samples containing pristine reinforcing steel with and without epoxy and reinforcing steel with 25 percent and 50 percent section reduction were embedded in concrete at 2.5 in. deep for laboratory evaluation. Two of the techniques, GPR and MFL, were used in a limited field test on the Iowa Highway 210 Bridge over Interstate 35 in Story County. The methods provide useful and complementary information. GPR provides a rapid approach to identify reinforcing steel that has anomalous responses. MFL provides similar detection responses but could be optimized to provide more quantitative correlation to actual condition. Full implementation could use either GPR or MFL methods to identify areas of concern, followed by radiography to give a visual image of the actual condition, providing the final guidance for maintenance actions." The full 103 page report and the 2 page Tech Transfer Summary are included in this link.
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Despite a trend of decreasing teen fatalities due to motor vehicle crashes over the past decade, they remain the leading cause of adolescent fatalities in Iowa. The purpose of this study was to create detailed case studies of each fatal motor vehicle crash involving a driver under the age of 20 that occurred in Iowa in 2009, 2010, and 2011. Data for each crash were gathered from media sources, law enforcement agencies, and the Iowa Department of Transportation. The driving records of the teens, which included their licensure history, prior traffic citations, and prior crashes, were also acquired. In addition, data about the charges filed against a teen as a result of being involved in a fatal crash were obtained. A total of 126 crashes involving 131 teen drivers that resulted in 143 fatalities were analyzed. Many findings for fatal crashes involving teen drivers in Iowa are consistent with national trends, including the overrepresentation of male drivers, crash involvement that increases with age, crash involvement per vehicle miles traveled that decreases with age, and prevalence of single-vehicle road departure crashes. Relative to national statistics, teen fatalities from crashes in Iowa are more likely to occur from midnight to 6am and from 9am to noon. Crash type varied by driver age and county population level. Teen drivers contributed to the fatal crashes at a rate of 74%; contribution of the teen driver was unknown for 11% of crashes. Speed was a factor for about 25% of the crashes for which a teen driver was at fault. The same was also true of alcohol/drug impairment. Only 20% of the rear-seat occupants of the teen drivers’ vehicles wore seat belts compared to 60% use for the front-seat occupants. Analysis of the teens’ driving records prior to the fatal crash suggests at-fault crashes and speeding violations are associated with contributing to the fatal crash.
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Weekly letting report.
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Weekly letting report.
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DESCRIPTION OF PROPOSED ACTION This Environmental Assessment (EA) has been prepared in compliance with the requirements of the National Environmental Policy Act of 1969 (NEPA). This EA informs the public and interested agencies of the proposed action and alternatives to the proposed action in order to gather feedback on the improvements under consideration. Proposed Action The Iowa Department of Transportation (Iowa DOT) and the Federal Highway Administration (FHWA) are evaluating potential alternatives to improve IA 122 in the City of Mason City. IA 122/Business US 18 is a primary east-west travel route through the City that transitions from a 4- lane undivided roadway, to 2-lane one-way pairs, then back to a 4-lane undivided roadway (Figure 1-1). The Iowa DOT proposes to flatten the tight reverse curves on the east end of the project. The one-way pairs will be narrowed by eliminating on-street parking along the corridor to more clearly define travel lanes. This will serve to calm traffic flows and reduce crashes along the highway. Additionally, improvements to intersections as well as consolidating or removing access points to improve traffic operations are proposed within the project corridor. A new access road for the Mason City Fire Department on the west end of the project will allow emergency trucks better access to travel south and east. Study Area The primary area of investigation for the Project is generally bounded by IA 122 through Mason City, known locally as 5th and 6th Street Southwest from South Monroe Avenue to South Carolina Avenue. US 65, known locally as Federal Avenue, bisects the study area. At this intersection of US 65 and Iowa 122, the 5th and 6th Street SW changes to 5th and 6th St SE. For the purposes of this discussion, this area will be referred to collectively as the IA 122 corridor. The Study Area boundaries were established to allow the development of a wide range of alternatives that could address the purpose and need for the project. The Study Area is larger than the area proposed for construction activities for the Project. However, some impacts may extend beyond the Study Area; where this occurs, it will be noted and addressed in the Environmental Analysis Section (Section 5). Figure 1-1 outlines the Study Area of the proposed action.
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Addendum to a report on a special investigation of the Iowa Department of Transportation for the period January 29, 1994 through June 30, 2013