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em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States


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Hispanics make up a growing percentage of the craft workers entering the construction industry, and this has created several challenges for American construction companies. This study addresses the situation by investigating training needs for Hispanic construction craft workers and developing a training program for them within the industry. In order to evaluate current craft workers’ conditions within the construction industry, Iowa State University researchers conducted a survey, with 98 Hispanic craft workers as respondents from 10 construction companies, to determine current working conditions. The results confirm that the language barrier is an obstacle for both the Hispanic workers and the English-speaking employees involved in construction projects. As a part of this research, two training courses were designed to help both American construction companies and their Hispanic labor force to overcome the barriers that keep them from succeeding safely and productively. A training course titled English as a Second Language Survival Course was developed to facilitate basic communication between Hispanic workers and their American supervisors using construction-focused terminology. This course was delivered once as a trial run for a two-hour duration and twice for a full-length duration of eight hours. Important feedback was obtained from participants as part of the evaluations of the course. “How much of the course contents will be useful in your working environment” was asked; 40% of workers said “all of it” and 60% said “most of it.” Another question was “Was it worth taking the time to attend the course?” to which 94% answered “definitely” and 6% answered “yes.” A second training course titled Stepping Up to Supervisor Course for Hispanic Construction Workers was also developed to provide an effective tool to help companies promote those Hispanic craft workers whose willingness and skills meet the requirements to advance to a supervisory position in an American construction company. This course will be offered in the spring of 2004.

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Four-lane undivided roadways in urban areas can experience a degradation of service and/or safety as traffic volumes increase. In fact, the existence of turning vehicles on this type of roadway has a dramatic effect on both of these factors. The solution identified for these problems is typically the addition of a raised median or two-way left-turn lane (TWLTL). The mobility and safety benefits of these actions have been proven and are discussed in the “Past Research” chapter of this report along with some general cross section selection guidelines. The cost and right-of-way impacts of these actions are widely accepted. These guidelines focus on the evaluation and analysis of an alternative to the typical four-lane undivided cross section improvement approach described above. It has been found that the conversion of a four-lane undivided cross section to three lanes (i.e., one lane in each direction and a TWLTL) can improve safety and maintain an acceptable level of service. These guidelines summarize the results of past research in this area (which is almost nonexistent) and qualitative/quantitative before-and-after safety and operational impacts of case study conversions located throughout the United States and Iowa. Past research confirms that this type of conversion is acceptable or feasible in some situations but for the most part fails to specifically identify those situations. In general, the reviewed case study conversions resulted in a reduction of average or 85th percentile speeds (typically less than five miles per hour) and a relatively dramatic reduction in excessive speeding (a 60 to 70 percent reduction in the number of vehicles traveling five miles per hour faster than the posted speed limit was measured in two cases) and total crashes (reductions between 17 to 62 percent were measured). The 13 roadway conversions considered had average daily traffic volumes of 8,400 to 14,000 vehicles per day (vpd) in Iowa and 9,200 to 24,000 vehicles per day elsewhere. In addition to past research and case study results, a simulation sensitivity analysis was completed to investigate and/or confirm the operational impacts of a four-lane undivided to three-lane conversion. First, the advantages and disadvantages of different corridor simulation packages were identified for this type of analysis. Then, the CORridor SIMulation (CORSIM) software was used x to investigate and evaluate several characteristics related to the operational feasibility of a four-lane undivided to three-lane conversion. Simulated speed and level of service results for both cross sections were documented for different total peak-hour traffic, access densities, and access-point left-turn volumes (for a case study corridor defined by the researchers). These analyses assisted with the identification of the considerations for the operational feasibility determination of a four -lane to three-lane conversion. The results of the simulation analyses primarily confirmed the case study impacts. The CORSIM results indicated only a slight decrease in average arterial speed for through vehicles can be expected for a large range of peak-hour volumes, access densities, and access-point left-turn volumes (given the assumptions and design of the corridor case study evaluated). Typically, the reduction in the simulated average arterial speed (which includes both segment and signal delay) was between zero and four miles per hour when a roadway was converted from a four-lane undivided to a three-lane cross section. The simulated arterial level of service for a converted roadway, however, showed a decrease when the bi-directional peak-hour volume was about 1,750 vehicles per hour (or 17,500 vehicles per day if 10 percent of the daily volume is assumed to occur in the peak hour). Past research by others, however, indicates that 12,000 vehicles per day may be the operational capacity (i.e., level of service E) of a three-lane roadway due to vehicle platooning. The simulation results, along with past research and case study results, appear to support following volume-related feasibility suggestions for four-lane undivided to three-lane cross section conversions. It is recommended that a four-lane undivided to three-lane conversion be considered as a feasible (with respect to volume only) option when bi-directional peak-hour volumes are less than 1,500 vehicles per hour, but that some caution begin to be exercised when the roadway has a bi-directional peak-hour volume between 1,500 and 1,750 vehicles per hour. At and above 1,750 vehicles per hour, the simulation indicated a reduction in arterial level of service. Therefore, at least in Iowa, the feasibility of a four-lane undivided to three-lane conversion should be questioned and/or considered much more closely when a roadway has (or is expected to have) a peak-hour volume of more than 1,750 vehicles. Assuming that 10 percent of the daily traffic occurs during the peak-hour, these volume recommendations would correspond to 15,000 and 17,500 vehicles per day, respectively. These suggestions, however, are based on the results from one idealized case xi study corridor analysis. Individual operational analysis and/or simulations should be completed in detail once a four-lane undivided to three-lane cross section conversion is considered feasible (based on the general suggestions above) for a particular corridor. All of the simulations completed as part of this project also incorporated the optimization of signal timing to minimize vehicle delay along the corridor. A number of determination feasibility factors were identified from a review of the past research, before-and-after case study results, and the simulation sensitivity analysis. The existing and expected (i.e., design period) statuses of these factors are described and should be considered. The characteristics of these factors should be compared to each other, the impacts of other potentially feasible cross section improvements, and the goals/objectives of the community. The factors discussed in these guidelines include • roadway function and environment • overall traffic volume and level of service • turning volumes and patterns • frequent-stop and slow-moving vehicles • weaving, speed, and queues • crash type and patterns • pedestrian and bike activity • right-of-way availability, cost, and acquisition impacts • general characteristics, including - parallel roadways - offset minor street intersections - parallel parking - corner radii - at-grade railroad crossings xii The characteristics of these factors are documented in these guidelines, and their relationship to four-lane undivided to three-lane cross section conversion feasibility identified. This information is summarized along with some evaluative questions in this executive summary and Appendix C. In summary, the results of past research, numerous case studies, and the simulation analyses done as part of this project support the conclusion that in certain circumstances a four-lane undivided to three-lane conversion can be a feasible alternative for the mitigation of operational and/or safety concerns. This feasibility, however, must be determined by an evaluation of the factors identified in these guidelines (along with any others that may be relevant for a individual corridor). The expected benefits, costs, and overall impacts of a four-lane undivided to three-lane conversion should then be compared to the impacts of other feasible alternatives (e.g., adding a raised median) at a particular location.

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This report is submitted as required per Code of Iowa section 327J.3(5), "The director shall report annually to the general assembly concerning the development and operation of the midwest regional rail system and the state's passenger rail service." The Midwest Regional Rail Initiative (MWRRI) is a nine-state effort to develop an implementation plan for a 3,000-mile, high-speed rail system hubbed in Chicago. Studies done since 1996 have concluded that such a regional system, including a line from Chicago to Omaha through Davenport, Iowa City and Des Moines, is viable. Most of the system would be upgraded to allow 110 mile-per-hour service. Some low volume lines, including the Iowa portions, would be upgraded for 79 mile-per-hour service. The nine-state coalition released an updated 2004 executive report for the system. As reported, the updated cost estimate for the Chicago to Omaha corridor, which includes a branch to Quincy, Ill., is $638 million for infrastructure and $167 million for rolling stock. These costs are higher than first estimated in 1998 and are given in 2002 dollars, (not adjusted for the cost of inflation). Operating subsidies would be required during an extended start-up phase. The allocation of these subsidy costs among the various states has not been determined, and is still a subject for analysis and negotiation. Little progress on implementation is expected unless a federal funding package is passed for passenger rail initiatives. Continued congressional discussion on policy directions relative to Amtrak clouds the issue of passenger rail funding. However, Congress is expected to address passenger rail issues and funding in 2007. Participation of the Iowa Department of Transportation in the MWRRI is authorized under Iowa Code section 327J.3.

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Secondary accident statistics can be useful for studying the impact of traffic incident management strategies. An easy-to-implement methodology is presented for classifying secondary accidents using data fusion of a police accident database with intranet incident reports. A current method for classifying secondary accidents uses a static threshold that represents the spatial and temporal region of influence of the primary accident, such as two miles and one hour. An accident is considered secondary if it occurs upstream from the primary accident and is within the duration and queue of the primary accident. However, using the static threshold may result in both false positives and negatives because accident queues are constantly varying. The methodology presented in this report seeks to improve upon this existing method by making the threshold dynamic. An incident progression curve is used to mark the end of the queue throughout the entire incident. Four steps in the development of incident progression curves are described. Step one is the processing of intranet incident reports. Step two is the filling in of incomplete incident reports. Step three is the nonlinear regression of incident progression curves. Step four is the merging of individual incident progression curves into one master curve. To illustrate this methodology, 5,514 accidents from Missouri freeways were analyzed. The results show that secondary accidents identified by dynamic versus static thresholds can differ by more than 30%.

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This brochure identifies each scenic byway route and the approximate mileage in terms of hard-surfaced and gravel roadways. Estimated driving time ranges from one and one-half hour to three and one-half hours, depending on your speed and the number of stops. These routes are offered for those of you who want to relax and stop often to enjoy the sights.

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Bypass traffic and experience a “scenic” change of pace by traveling along Iowa’s scenic byways. Iowa’s eight state-designated and two nationally-designated scenic byways are a great way to experience Iowa’s natural beauty, history and culture. Stop to smell the wildflowers or listen to the songbirds, or follow an impulse to take a side trip to one of the many attractions and countryside hamlets. A camera is a must for these postcard-perfect vistas. You never know when you will encounter a bald eagle along the Mississippi River, rare plants and animals in the Loess Hills, or the exceptional architecture of unique barns, churches and other buildings along the routes. This brochure identifies each scenic byway route and the approximate mileage in terms of hard-surfaced and gravel roadways. Estimated driving time ranges from one and one-half hour to three and one-half hours, depending on your speed and the number of stops. These routes are offered for those of you who want to relax and stop often to enjoy the sights.

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The role of rural demand-responsive transit is changing, and with that change is coming an increasing need for technology. As long as rural transit was limited to a type of social service transportation for a specific set of clients who primarily traveled in groups to common meal sites, work centers for the disabled, or clinics in larger communities, a preset calendar augmented by notes on a yellow legal pad was sufficient to develop schedules. Any individual trips were arranged at least 24 to 48 hours ahead of time and were carefully scheduled the night before in half-hour or twenty-minute windows by a dispatcher who knew every lane in the service area. Since it took hours to build the schedule, any last-minute changes could wreak havoc with the plans and raise the stress level in the dispatch office. Nevertheless, given these parameters, a manual scheduling system worked for a small demand-responsive operation.

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Since the introduction of expanded levels of intrastate service on October 30, 2006, Amtrak trains in Illinois have produced impressive gains in both ridership and ticket revenue. This success and continuing stakeholder support has given rise to a formal request from the Illinois Department of Transportation (“Ill. DOT”) to Amtrak to develop a feasibility study regarding possible service consisting of a morning and an evening train in each direction between Chicago and the Quad Cities. The area between Chicago and the Quad Cities includes many rapidly growing communities. From Chicago toward the West and South, many towns and cities have experienced double digit growth increases in population since the year 2000. Southern DuPage, Cook and Will counties have seen especially strong growth, pressuring highway infrastructure, utilities, and schools. Community development and highway congestion are readily apparent when traveling the nearly 3 hour, 175 mile route between Chicago and the Quad Cities. As information, there are only three weekday round trip bus frequencies available between Chicago and the Quad Cities. The Quad City International Airport offers a total of 10 daily scheduled round trip flights to Chicago's O'Hare International Airport via two separate carriers flying regional jets. The Quad Cities (Davenport, Moline, Rock Island, and Bettendorf) are located along the Mississippi River. Nearly 60% of its visitors are from the Chicago area. With dozens of miles of scenic riverfront, river boating, casinos, and thousands of acres of expansive public spaces, the Quad Cities area is a major draw from both Iowa and Illinois. The huge Rock Island Arsenal, one of the largest military arsenals in the country and located along the river, is transitioning to become the headquarters of the United States First Army. As will be discussed later in the report, there is only one logical rail route through the Quad Cities themselves. The Iowa Interstate Railroad operates through the Quad Cities along the river and heads west through Iowa. The Quad Cities are considering at least three potential locations for an Amtrak station. A study now underway supported by several local stakeholders will recommend a site which will then be considered, given available local and other financial support. If Amtrak service were to terminate in the Quad Cities, an overnight storage track of sufficient length along with ample parking and certain other requirements covered elsewhere in the report would be required.

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This report documents Phase IV of the Highway Maintenance Concept Vehicle (HMCV) project, a pooled fund study sponsored by the Departments of Transportation of Iowa, Pennsylvania, and Wisconsin. This report provides the background, including a brief history of the earlier phases of the project, a systems overview, and descriptions of the research conducted in Phase IV. Finally, the report provides conclusions and recommendations for future research. Background The goal of the Highway Maintenance Concept Vehicle Pooled Fund Study is to provide travelers with the level of service defined by policy during the winter season at the least cost to taxpayers. This goal is to be accomplished by using information regarding actual road conditions to facilitate and adjust snow and ice control activities. The approach used in this study was to bring technology applications from other industries to the highway maintenance vehicle. This approach is evolutionary in that as emerging technologies and applications are found to be acceptable to the pooled fund states and as they appear that to have potential for supporting the study goals they become candidates for our research. The objective of Phase IV is to: Conduct limited deployment of selected technologies from Phase III by equipping a vehicle with proven advanced technologies and creating a mobile test laboratory for collecting road weather data. The research quickly pointed out that investments in winter storm maintenance assets must be based on benefit/cost analysis and related to improving level of service. For example, Iowa has estimated the average cost of fighting a winter storm to be about $60,000 to $70,000 per hour typically. The maintenance concept vehicle will have advanced technology equipment capable of applying precisely the correct amount of material, accurately tailored to the existing and predicted pavement conditions. Hence, a state using advanced technology could expect to have a noticeable impact on the average time taken to establish the winter driving service level. If the concept vehicle and data produced by the vehicle are used to support decision-making leading to reducing material usage and the average time by one hour, a reasonable benefit/cost will result. Data from the friction meter can be used to monitor and adjust snow and ice control activities and inform travelers of pavement surface conditions. Therefore, final selection of successfully performing technologies will be based on the foundation statements and criteria developed by the study team.

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The focus of this report is a capacity analysis of two long-term urban freeway Work Zones. Work Zone #1 tapered four mainline lanes to two, using two separate tapers; Work Zone #2 tapered two mainline lanes to one. Work Zone throughput was analyzed throughout the day over multiple days and traffic operations conditions were analyzed up to a distance of five miles upstream of the Work Zone entrance. Historical data from pavement-embedded detectors were used to analyze traffic conditions. The database consisted of five-minute volume, speed and occupancy data collected from 78 detectors for a total of 50 days. Congestion during each analyzed Work Zone existed for more than fourteen hours each day; Work Zone impacts adversely affected freeway operations over distances of 3.7 to 4.2 miles. Speed and occupancy conditions further upstream were, however, not affected, or even improved due to significant trip diversion. Work Zone capacity was defined based on the maximum traffic flows observed over a one-hour period; throughput values were also compiled over longer periods of time when traffic was within 90% of the maximum observed one-hour flows, as well as over the multi-hour mid-day period. The Highway Capacity Manual freeway capacity definition based on the maximum observed 15-min period was not used, since it would have no practical application in estimating Work Zone throughput when congested conditions prevail for the majority of the hours of the day. Certain noteworthy changes took place for the duration of the analyzed Work Zones: per-lane throughput dropped; morning peak periods started earlier, evening peak periods ended later and lasted longer; mid-day volumes dropped accompanied by the highest occupancies of the day. Trip diversion was evident in lower volumes entering the analyzed freeway corridor, higher volumes using off-ramps and lower volumes using onramps upstream of the Work Zones. The majority of diverted traffic comprised smaller vehicles (vehicles up to 21 feet in length); combination truck volumes increased and their use of the median lane increased, contrary to smaller vehicles that shifted toward a heavier use of the shoulder lane.

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Drainage-basin and channel-geometry multiple-regression equations are presented for estimating design-flood discharges having recurrence intervals of 2, 5, 10, 25, 50, and 100 years at stream sites on rural, unregulated streams in Iowa. Design-flood discharge estimates determined by Pearson Type-III analyses using data collected through the 1990 water year are reported for the 188 streamflow-gaging stations used in either the drainage-basin or channel-geometry regression analyses. Ordinary least-squares multiple-regression techniques were used to identify selected drainage-basin and channel-geometry regions. Weighted least-squares multiple-regression techniques, which account for differences in the variance of flows at different gaging stations and for variable lengths in station records, were used to estimate the regression parameters. Statewide drainage-basin equations were developed from analyses of 164 streamflow-gaging stations. Drainage-basin characteristics were quantified using a geographic-information-system (GIS) procedure to process topographic maps and digital cartographic data. The significant characteristics identified for the drainage-basin equations included contributing drainage area, relative relief, drainage frequency, and 2-year, 24-hour precipitation intensity. The average standard errors of prediction for the drainage-basin equations ranged from 38.6% to 50.2%. The GIS procedure expanded the capability to quantitatively relate drainage-basin characteristics to the magnitude and frequency of floods for stream sites in Iowa and provides a flood-estimation method that is independent of hydrologic regionalization. Statewide and regional channel-geometry regression equations were developed from analyses of 157 streamflow-gaging stations. Channel-geometry characteristics were measured on site and on topographic maps. Statewide and regional channel-geometry regression equations that are dependent on whether a stream has been channelized were developed on the basis of bankfull and active-channel characteristics. The significant channel-geometry characteristics identified for the statewide and regional regression equations included bankfull width and bankfull depth for natural channels unaffected by channelization, and active-channel width for stabilized channels affected by channelization. The average standard errors of prediction ranged from 41.0% to 68.4% for the statewide channel-geometry equations and from 30.3% to 70.0% for the regional channel-geometry equations. Procedures provided for applying the drainage-basin and channel-geometry regression equations depend on whether the design-flood discharge estimate is for a site on an ungaged stream, an ungaged site on a gaged stream, or a gaged site. When both a drainage-basin and a channel-geometry regression-equation estimate are available for a stream site, a procedure is presented for determining a weighted average of the two flood estimates.

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Researchers should continuously ask how to improve the models we rely on to make financial decisions in terms of the planning, design, construction, and maintenance of roadways. This project presents an alternative tool that will supplement local decision making but maintain a full appreciation of the complexity and sophistication of today’s regional model and local traffic impact study methodologies. This alternative method is tailored to the desires of local agencies, which requested a better, faster, and easier way to evaluate land uses and their impact on future traffic demands at the sub-area or project corridor levels. A particular emphasis was placed on scenario planning for currently undeveloped areas. The scenario planning tool was developed using actual land use and roadway information for the communities of Johnston and West Des Moines, Iowa. Both communities used the output from this process to make regular decisions regarding infrastructure investment, design, and land use planning. The City of Johnston case study included forecasting future traffic for the western portion of the city within a 2,600-acre area, which included 42 intersections. The City of West Des Moines case study included forecasting future traffic for the city’s western growth area covering over 30,000 acres and 331 intersections. Both studies included forecasting a.m. and p.m. peak-hour traffic volumes based upon a variety of different land use scenarios. The tool developed took goegraphic information system (GIS)-based parcel and roadway information, converted the data into a graphical spreadsheet tool, allowed the user to conduct trip generation, distribution, and assignment, and then to automatically convert the data into a Synchro roadway network which allows for capacity analysis and visualization. The operational delay outputs were converted back into a GIS thematic format for contrast and further scenario planning. This project has laid the groundwork for improving both planning and civil transportation decision making at the sub-regional, super-project level.

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An expert system has been developed that provides 24 hour forecasts of roadway and bridge frost for locations in Iowa. The system is based on analysis of frost observations taken by highway maintenance personnel, analysis of conditions leading to frost as obtained from meteorologists with experience in forecasting bridge and roadway frost, and from fundamental physical principles of frost processes. The expert system requires the forecaster to enter information on recent maximum and minimum temperatures and forecasts of maximum and minimum air temperatures, dew point temperatures, precipitation, cloudiness, and wind speed. The system has been used operationally for the last two frost seasons by Freese-Notis Associates, who have been under contract with the Iowa DOT to supply frost forecasts. The operational meteorologists give the system their strong endorsement. They always consult the system before making a frost forecast unless conditions clearly indicate frost is not likely. In operational use, the system is run several times with different input values to test the sensitivity of frost formation on a particular day to various meteorological parameters. The users comment. that the system helps them to consider all the factors relevant to frost formation and is regarded as an office companion for making frost forecasts.

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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 1 - Basic Introduction to the Use of International Units of Measurement. This module is designed for use by all levels of personnel, primarily office staff, and provides a basic background in the use of metric measurements in both written and oral communications.

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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 2 - Construction and Maintenance Operations and Reporting. This module provides hands on examples of applications of metric measurements in the construction and maintenance field operations.