Evaluation of Different Methods to Calculate Heavy-Truck VMT, Final Report, December 2004

Reliable estimates of heavy-truck volumes are important in a number of transportation applications. Estimates of truck volumes are necessary for pavement design and pavement management. Truck volumes are important in traffic safety. The number of trucks on the road also influences roadway capacity and traffic operations. Additionally, heavy vehicles pollute at higher rates than passenger vehicles. Consequently, reliable estimates of heavy-truck vehicle miles traveled (VMT) are important in creating accurate inventories of on-road emissions. This research evaluated three different methods to calculate heavy-truck annual average daily traffic (AADT) which can subsequently be used to estimate vehicle miles traveled (VMT). Traffic data from continuous count stations provided by the Iowa DOT were used to estimate AADT for two different truck groups (single-unit and multi-unit) using the three methods. The first method developed monthly and daily expansion factors for each truck group. The second and third methods created general expansion factors for all vehicles. Accuracy of the three methods was compared using n-fold cross-validation. In n-fold cross-validation, data are split into n partitions, and data from the nth partition are used to validate the remaining data. A comparison of the accuracy of the three methods was made using the estimates of prediction error obtained from cross-validation. The prediction error was determined by averaging the squared error between the estimated AADT and the actual AADT. Overall, the prediction error was the lowest for the method that developed expansion factors separately for the different truck groups for both single- and multi-unit trucks. This indicates that use of expansion factors specific to heavy trucks results in better estimates of AADT, and, subsequently, VMT, than using aggregate expansion factors and applying a percentage of trucks. Monthly, daily, and weekly traffic patterns were also evaluated. Significant variation exists in the temporal and seasonal patterns of heavy trucks as compared to passenger vehicles. This suggests that the use of aggregate expansion factors fails to adequately describe truck travel patterns.

Development of a Method to Determine Pavement Damage Due to Detours, Project 02-105, Apirl 2005

The research presented in this report provides the basis for the development of a new procedure to be used by the Iowa DOT and cities and counties in the state to deal with detours. Even though the project initially focused on investigating new tools to determine condition and compensation, the focus was shifted to traffic and the gas tax method to set the basis for the new procedure. It was concluded that the condition-based approach, even though accurate and consistent condition evaluations can be achieved, is not feasible or cost effective because of the current practices of data collection (two-year cycle) and also the logistics of the procedure (before and after determination). The gas tax method provides for a simple, easy to implement, and consistent approach to dealing with compensation for use of detours. It removes the subjectivity out of the current procedures and provides for a more realistic (traffic based) approach to the compensation determination.

Study Regarding Implementation of a Uniform Statewide System to Allow for Electronic Transactions for the Registration and Titling of Motor Vehicles

LEGISLATIVE STUDY – The 83rd General Assembly of the Iowa Legislature, in Senate File 2273, directed the Iowa Department of Transportation (DOT) to conduct a study of how to implement a uniform statewide system to allow for electronic transactions for the registration and titling of motor vehicles. PARTICIPANTS IN STUDY – As directed by Senate File 2273, the DOT formed a working group to conduct the study that included representatives from the Consumer Protection Division of the Office of the Attorney General, the Department of Public Safety, the Department of Revenue, the Iowa State County Treasurer’s Association, the Iowa Automobile Dealers Association, and the Iowa Independent Automobile Dealers Association. CONDUCT OF THE STUDY – The working group met eight times between June 17, 2010, and October 1, 2010. The group discussed the costs and benefits of electronic titling from the perspectives of new and used motor vehicle dealers, county treasurers, the DOT, lending institutions, consumers and consumer protection, and law enforcement. Security concerns, legislative implications, and implementation timelines were also considered. In the course of the meetings the group: 1. Reviewed the specific goals of S.F. 2273, and viewed a demonstration of Iowa’s current vehicle registration and titling system so participants that were not users of the system could gain an understanding of its current functionality and capabilities. 2. Reviewed the results of a survey of county treasurers conducted by the DOT to determine the extent to which county treasurers had processing backlogs and the extent to which county treasurers limited the number of dealer registration and titling transactions that they would process in a single day and while the dealer waited. Only eight reported placing a limit on the number of dealer transactions that would be processed while the dealer waited (with the number ranging from one to four), and only 11 reported a backlog in processing registration and titling transactions as of June 11, 2010, with most backlogs being reported in the range of one to three days. 3. Conducted conference calls with representatives of the American Association of Motor Vehicle Administrators (AAMVA) and representatives of three states -- Kansas, which has an electronic lien and titling (ELT) program, and Wisconsin and Florida, each of which have both an ELT program and an electronic registration and titling (ERT) program – to assess current and best practices for electronic transactions. In addition, the DOT (through AAMVA) submitted a survey to all U.S. jurisdictions to determine how, if at all, other states implemented electronic transactions for the registration and titling of motor vehicles. Twenty-eight states responded to the survey; of the 28 states that responded, only 13 allowed liens to be added or released electronically, and only five indicated allowing applications for registration and titling to be submitted electronically. DOT staff also heard a presentation from South Dakota on its ERT system at an AAMVA regional meeting. ELT information that emerged suggests a multi-vendor approach, in which vendors that meet state specifications for participation are authorized to interface with the state’s system to serve as a portal between lenders and the state system, will facilitate electronic lien releases and additions by offering lenders more choices and the opportunity to use the same vendor in multiple states. The ERT information that emerged indicates a multi-interface approach that offers an interface with existing dealer management software (DMS) systems and through a separate internet site will facilitate ERT by offering access that meets a variety of business needs and models. In both instances, information that emerged indicates that, in the long-term, adoption rates are positively affected by making participation above a certain minimum threshold mandatory. 4. To assess and compare functions or services that might be offered by or through a vendor, the group heard presentations from vendors that offer products or services that facilitate some aspect of ELT or ERT. 5. To assess the concerns, needs and interest of Iowa motor vehicle dealers, the group surveyed dealers to assess registration and titling difficulties experienced by dealers, the types of DMS systems (if any) used by dealers, and the dealers’ interest and preference in using an electronic interface to submit applications for registration and titling. Overall, 40% of the dealers that responded indicated interest and 57% indicated no interest, but interest was pronounced among new car dealers (75% were interested) and dealers with a high number of monthly transactions (85% of dealers averaging more than 50 sales per month were interested). The majority of dealers responding to the dealer survey ranked delays in processing and problems with daily limits on transaction as ―minor difficulty or ―no difficulty. RECOMMENDATIONS -- At the conclusion of the meetings, the working group discussed possible approaches for implementation of electronic transactions in Iowa and reached a consensus that a phased implementation of electronic titling that addressed first electronic lien and title transactions (ELT) and electronic fund transfers (EFT), and then electronic applications for registration and titling (ERT) is recommended. The recommendation of a phased implementation is based upon recognition that aspects of ELT and EFT are foundational to ERT, and that ELT and EFT solutions are more readily and easily attained than the ERT solution, which will take longer and be somewhat more difficult to develop and will require federal approval of an electronic odometer statement to fully implement. ELT – A multi-vendor approach is proposed for ELT. No direct costs to the state, counties, consumers, or dealers are anticipated under this approach. The vendor charges participating lenders user or transaction fees for the service, and it appears the lenders typically absorb those costs due to the savings offered by ELT. Existing staff can complete the programming necessary to interface the state system with vendors’ systems. The estimated time to implement ELT is six to nine months. Mandatory participation is not recommended initially, but should be considered after ELT has been implemented and a suitable number of vendors have enrolled to provide a fair assessment of participation rates and opportunities. EFT – A previous attempt to implement ELT and EFT was terminated due to concern that it would negatively impact county revenues by reducing interest income earned on state funds collected by the county and held until the monthly transfer to the state. To avoid that problem in this implementation, the EFT solution should remain revenue neutral to the counties, by allowing fees submitted by EFT to be immediately directed to the proper county account. Because ARTS was designed and has the capacity to accommodate EFT, a vendor is not needed to implement EFT. The estimated time to implement EFT is six to nine months. It is expected that EFT development will overlap ELT development. ERT – ERT itself must be developed in phases. It will not be possible to quickly implement a fully functioning, paperless ERT system, because federal law requires that transfer of title be accompanied by a written odometer statement unless approval for an alternate electronic statement is granted by the National Highway Traffic Safety Administration (NHTSA). It is expected that it will take as much as a year or more to obtain NHTSA approval, and that NHTSA approval will require design of a system that requires the seller to electronically confirm the seller’s identity, make the required disclosure to the buyer, and then transfer the disclosure to the buyer, who must also electronically confirm the buyer’s identity and electronically review and accept the disclosure to complete and submit the transaction. Given the time that it will take to develop and gain approval for this solution, initial ERT implementation will focus on completing and submitting applications and issuing registration applied for cards electronically, with the understanding that this process will still require submission of paper documents until an electronic odometer solution is developed. Because continued submission of paper documents undermines the efficiencies sought, ―full‖ ERT – that is, all documents necessary for registration and titling should be capable of approval and/or acceptance by all parties, and should be capable of submission without transmittal or delivery of duplicate paper documents .– should remain the ultimate goal. ERT is not recommended as a means to eliminate review and approval of registration and titling transactions by the county treasurers, or to place registration and titling approval in the hands of the dealers, as county treasurers perform an important role in deterring fraud and promoting accuracy by determining the genuineness and regularity of each application. Authorizing dealers to act as registration agents that approve registration and title applications, issue registration receipts, and maintain and deliver permanent metal license plates is not recommended. Although distribution of permanent plates by dealers is not recommended, it is recommended that dealers participating in ERT generate and print registration applied for cards electronically. Unlike the manually-issued cards currently in use, cards issued in this fashion may be queried by law enforcement and are less susceptible to misuse by customers and dealers. The estimated time to implement the electronic application and registration applied for cards is 12 to 18 months, to begin after ELT and EFT have been implemented. It is recommended that focus during this time be on facilitating transfers through motor vehicle dealers, with initial deployment focused on higher-volume dealers that use DMS systems. In the long term an internet option for access to ERT must also be developed and maintained to allow participation for lower-volume dealers that do not use a DMS system. This option will also lay the ground work for an ERT option for sales between private individuals. Mandatory participation in Iowa is not recommended initially. As with ELT, it is recommended that mandatory participation be considered after at least an initial phase of ERT has been implemented and a suitable number of dealers have enrolled to provide a fair assessment of participation rates and opportunities. The use of vendors to facilitate ERT is not initially proposed because 1) DOT IT support staff is capable of developing a system that will interact with DMS systems and will still have to develop a dealer and public interface regardless of whether a vendor acts as intermediary between the DMS systems, and 2) there is concern that the cost of the vendor-based system, which is funded by transaction-based payments from the dealer to the vendor, will be passed to the consumer in the form of additional documentation or conveyance fees. However, the DOT recommends flexibility on this point, as development and pilot of the system may indicate that a multi-vendor approach similar to that recommended for ELT may increase the adoption rate by larger dealers and may ultimately decrease the user management to be exercised by DOT staff. If vendors are used in the process, additional legislation or administrative rules may be needed to control the fees that may be passed to the consumer. No direct cost to the DOT or county treasurers is expected, as the DOT expects that it may complete necessary programming with existing staff. Use of vendors to facilitate ERT transactions by dealers using DMS systems would result in transaction fees that may ultimately be passed to consumers. LEGISLATION – As a result of the changes implemented in 2004 under Senate File 2070, the only changes to Iowa statutes proposed are to section 321.69 of the Iowa Code, ―Damage disclosure statement,and section 321.71, ―Odometer requirements.‖ In each instance, authority to execute these statements by electronic means would be clarified by authorizing language similar to that used in section 321.20, subsections ―2‖ and ―3,‖ which allows for electronic applications and directs the department to ―adopt rules on the method for providing signatures for applications made by electronic means.‖ In these sections, the authorizing language might read as follows: Notwithstanding contrary provisions of this section, the department may develop and implement a program to allow for any statement required by this section to be made electronically. The department shall adopt rules on the method for providing signatures for statements made by electronic means. Some changes to DOT administrative rules will be useful but only to enable changes to work processes that would be desirable in the long term. Examples of long term work processes that would be enabled by rule changes include allowing for signatures created through electronic means and electronic odometer certifications. The DOT rules, as currently written, do not hinder the ability to proceed with ELT, EFT, and ERT.

A Computerized Method for the Hydrologic Design of Culverts, February 1974

Nationwide, about five cents of each highway construction dollar is spent on culverts. In Iowa, average annual construction costs on the interstate, primary, and federal-aid secondary systems are about $120,000,000. Assuming the national figure applies to Iowa, about $6,000,000 are spent on culvert construction annually. For each one percent reduction in overall culvert costs, annual construction costs would be reduced by $60,000. One area of potential cost reduction lies in the sizing of the culvert. Determining the flow area and hydraulic capacity is accomplished in the initial design of the culvert. The normal design sequence is accomplished in two parts. The hydrologic portion consists of the determination of a design discharge in cubic feet per second using one of several available methods. This discharge is then used directly in the hydraulic portion of the design to determine the proper type, size, and shape of culvert to be used, based on various site and design restrictions. More refined hydrologic analyses, including rainfall-runoff analysis, flood hydrograph development, and streamflow routing techniques, are not pursued in the existing design procedure used by most county and state highway engineers.

Method for Estimating the Magnitude and Frequency of Floods at Ungaged Sites on Unregulated Rural Streams in Iowa, HR-268, 1987

This report provides techniques and procedures for estimating the probable magnitude and frequency of floods at ungaged sites on Iowa streams. Physiographic characteristics were used to define the boundaries of five hydrologic regions. Regional regression equations that relate the size of the drainage area to flood magnitude are defined for estimating peak discharges having specified recurrence intervals of 2, 5, 10, 25, 50, and 100 years. Regional regression equations are applicable to sites on streams that have drainage areas ranging from 0.04 to 5,150 square miles provided that the streams are not affected significantly by regulation upstream from the sites and that the drainage areas upstream from the sites are not mostly urban areas. Flood-frequency characteristics for the mainstems of selected rivers are presented in graphs as a function of drainage area.

Automatic Tracer-Dilution Method Used for Stage-Discharge Ratings and Streamflow Hydrographs on Small Iowa Streams, HR-285, 1990

An automatic system was designed to concurrently measure stage and discharge for the purpose of developing stage-discharge ratings and high flow hydrographs on small streams. Stage, or gage height, is recorded by an analog-to-digital recorder and discharge is determined by the constant-rate tracer-dilution method. The system measures flow above a base stage set by the user. To test the effectiveness of the system and its components, eight systems, with a variety of equipment, were installed at crest-stage gaging stations across Iowa. A fluorescent dye, rhodamine-WT, was used as the tracer. Tracer-dilution discharge measurements were made during 14 flow periods at six stations from 1986 through 1988 water years. Ratings were developed at three stations with the aid of these measurements. A loop rating was identified at one station during rapidly-changing flow conditions. Incomplete mixing and dye loss to sediment apparently were problems at some stations. Stage hydrographs were recorded for 38 flows at seven stations. Limited data on background fluorescence during high flows were also obtained.

Development of a Rational Characterization Method for Iowa Fly Ash, HR-286, 1988

This research project was conducted in an attempt to determine the cause of paste strength variability in Iowa fly ashes and to develop test methods to more adequately reflect fly ash physical and chemical characteristics. An extensive three year sampling and testing program was developed and initiated which incorporated fly ash from several Iowa power plants. Power plant design and operating data were collected. The variability was directly linked to power plant maintenance schedules and to sodium carbonate coal pretreatment. Fly ash physical and chemical properties can change drastically immediately before and after a maintenance outage. The concentrations of sulfate bearing minerals in the fly ash increases sharply during shutdown. Chemical, mineralogical, and physical testing indicated that the sodium, sulfate bearing minerals, lime and tricalcium aluminate contents of the fly ashes play important roles in the development of hydration reaction products in fly ash pastes. The weak pastes always contained ettringite as the major reaction product. The strong pastes contained straetlingite and monosulfoaluminate as the major reaction products along with minor amounts of ettringite. Recommendations for testing procedure changes and suggested interim test methods are presented.

A Nondestructive Method for Determining the Thickness of Sound Concrete on Older Pavements, HR-250, 1983

The primary purpose of this project was to assess the potential of a nondestructive remote sensing system, specifically, ground penetrating subsurface interface radar, for identification and evaluation of D-cracking pavement failures. A secondary purpose was to evaluate the effectiveness of this technique for locating voids under pavements and determining the location of steel reinforcement. From the data collected and the analysis performed to date, the following conclusions can be made regarding the ground penetrating radar system used for this study: (1) steel reinforcement can be accurately located; (2) pavement thickness can be determined; (3) distressed areas in pavements can be located and broadly classified as to severity of deterioration; (4) voids under pavements can be located; and (5) higher resolution recording equipment is required to accurately determine both the thickness of sound pavement remaining over distressed areas and the depth of void areas under pavements.

New Method for Breaking High Strength Prestress Cable, MLR-97-6, 1997

A new method was developed for breaking high strength prestressed cable. The old method used an aluminum oxide grit packed into a special gripping jaw. The new method uses aluminum shims wrapped around the cable and then is gripped with a V-grip. The new method gives nearly 100% "good breaks" on the cable compared to approximately 10% good breaks with the old method. In addition, the new cable breaking method gives higher ultimate tensile strengths, is more reproducible, is quicker, cleaner and easier on equipment.

An Adaptive Field Detection Method For Bridge Scour Monitoring Using Motion-Sensing Radio Transponders (RFIDs), TR-617, 2014

A comprehensive field detection method is proposed that is aimed at developing advanced capability for reliable monitoring, inspection and life estimation of bridge infrastructure. The goal is to utilize Motion-Sensing Radio Transponders (RFIDS) on fully adaptive bridge monitoring to minimize the problems inherent in human inspections of bridges. We developed a novel integrated condition-based maintenance (CBM) framework integrating transformative research in RFID sensors and sensing architecture, for in-situ scour monitoring, state-of-the-art computationally efficient multiscale modeling for scour assessment.

New Method for Breaking High Strength Prestress Cable, MLR-97-6, 1997

A new method was developed for breaking high strength prestressed cable. The old method used an aluminum oxide grit packed into a special gripping jaw. The new method uses aluminum shims wrapped around the cable and then is gripped with a V-grip. The new method gives nearly 100% "good breaks" on the cable compared to approximately 10% good breaks with the old method. In addition, the new cable breaking method gives higher ultimate tensile strengths, is more reproducible, is quicker, cleaner and easier on equipment.

An Investigation of the Chemical Method of Determining the Cement Content of Hardened Concrete, MLR-71-01 and R-248, 1971

The Iowa State Highway Commission Laboratory is called upon to determine the cement content of hardened concrete when field problems relating to batch weights are encountered. The standard test for determining the cement content is ASTM C-85. An investigation of this method by the New Jersey State Highway Department involving duplicate samples and four cooperating laboratories produced very erratic results, however, the results obtained by this method have not been directly compared to known cement contents of concrete made with various cements and various aggregates used in Iowa.

A Laboratory Investigation of An Accelerated Polishing Method for Determining the Skid Resistance Potential of Aggregates, MLR-76-02 and R-264, 1976

An initial feasibility study indicated that the "Purdue Accelerated Polishing Method" gave repeatable results when testing the skid resistance of laboratory specimens. The results also showed a rough correlation with the field performance of the same aggregate sources. The research was then expanded to include all available asphalt aggregates. The results of the expanded study indicated that the method is not presently capable of developing and measuring the full skid potential of the various aggregate sources. Further research in the area of polishing times and/or pressures is needed.

Iowa Fen Rapid Assessment Method for Wetlands v. 1 Quantitative Rating, 2016

Rapid assessment methods are valuable tools for collecting information about the quality and status of natural systems. However, they are not a substitute for detailed surveys of those systems. Users of this method should consider that the method may under-score or over-score the site that’s assessed, especially when the site is not a typical fen (i.e. a sedge meadow could score lower than fens, but in-fact be a relatively high quality sedge meadow). This assessment can be used throughout most of the spring, summer and fall period, however the ideal “index period” would be from late May through early October when native plant communities, as well as invasive species, are most apparent.