Iowa’s Bridge and Highway Climate Change and Extreme Weather Vulnerability Assessment Pilot, HEPN-707, 2015

The Iowa Department of Transportation (DOT) is responsible for approximately 4,100 bridges and structures that are a part of the state’s primary highway system, which includes the Interstate, US, and Iowa highway routes. A pilot study was conducted for six bridges in two Iowa river basins—the Cedar River Basin and the South Skunk River Basin—to develop a methodology to evaluate their vulnerability to climate change and extreme weather. The six bridges had been either closed or severely stressed by record streamflow within the past seven years. An innovative methodology was developed to generate streamflow scenarios given climate change projections. The methodology selected appropriate rainfall projection data to feed into a streamflow model that generated continuous peak annual streamflow series for 1960 through 2100, which were used as input to PeakFQ to estimate return intervals for floods. The methodology evaluated the plausibility of rainfall projections and credibility of streamflow simulation while remaining consistent with U.S. Geological Survey (USGS) protocol for estimating the return interval for floods. The results were conveyed in an innovative graph that combined historical and scenario-based design metrics for use in bridge vulnerability analysis and engineering design. The pilot results determined the annual peak streamflow response to climate change likely will be basin-size dependent, four of the six pilot study bridges would be exposed to increased frequency of extreme streamflow and would have higher frequency of overtopping, the proposed design for replacing the Interstate 35 bridges over the South Skunk River south of Ames, Iowa is resilient to climate change, and some Iowa DOT bridge design policies could be reviewed to consider incorporating climate change information.

Iowa DOT Evaluation of the PASCO Road Survey System, HR-539, 1987

The report compares and contrasts the automated PASCO method of pavement evaluation to the manual procedures used by the Iowa Department of Transportation (DOT) to evaluate pavement condition. Iowa DOT's use of IJK and BPR roadmeters and manual crack and patch surveys are compared to PASCO's use of 35-mm photography, artificial lighting and hairline projection, tracking wheels and lasers to measure ride, cracking and patching, rut depths, and roughness. The Iowa DOT method provides a Present Serviceability Index (PSI) value and PASCO provides a Maintenance Control Index (MCI). Seven sections of Interstate Highway, county roads and city streets, and one shoulder section were tested with different speeds of data collection, surface types and textures, and stop and start conditions. High correlation of results between the two methods in the measurement of roughness (0.93 for the tracking wheel and 0.84 for the laser method) were recorded. Rut depth correlations of 0.61 and cracking of 0.32 are attributed to PASCO's more comprehensive measurement techniques. A cost analysis of the data provided by both systems indicates that PASCO is capable of providing a comparable result with improved accuracy at a cost of $125-$150 or less per two-lane mile depending on survey mileage. Improved data collection speed, accuracy, and reliability, and a visible record of pavement condition for comparable costs are available. The PASCO system's ability to provide the data required in the Highway Pavement Distress Identification Manual, the Pavement Condition Rating Guide, and the Strategic Highway Research Program Long Term Pavement Performance (LTPP) Studies, is also outlined in the report.

Evaluation of the PAVEDEX Road Survey System in Iowa, HR-547, 1990

The Iowa Department of Transportation (DOT) evaluated the PAS I Road Survey System from PAVEDEX, Inc. of Spokane, Washington. This system uses video photograph to identify and quantify pavement cracking and patching distresses. Comparisons were made to procedures currently used in the State. Interstate highway, county roads and city streets, and two shoulder sections were evaluated. Variables included travel speeds, surface type and texture, and traffic control conditions. Repeatability and distress identification were excellent on rigid pavements. Differences in distress identification and the effect of surface textures in the flexible test sections limited the repeatability and correlation of data to that of the Iowa DOT method. Cost data indicates that PAVEDEX is capable of providing comparable results with improved accuracy at a reasonable cost, but in excess of that experienced currently by the Iowa DOT. PAVEDEX is capable of providing network level pavement condition data at highway speeds and analysis of the data to identify 1/8-inch cracks at approximately 2-3 lane miles per hour with manual evaluation. Photo-logging capability is also included in the unit.

2009-2013 Iowa Transportation Improvement Program

The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state's transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. Iowa's transportation system is multi-modal; therefore, the Program encompasses investments in aviation, transit, railroads, trails, and highways. A major component of the Program is the highway section. The FY2009-2013 highway section is financially balanced and was developed to achieve several objectives. The Commission's primary highway investment objective is the safety, maintenance and preservation of Iowa's existing highway system. The Commission has allocated an annual average of $321 million to achieve this objective. This includes $185 million in 2009 and $170 million annually in years 2010-2013 for preserving the interstate system. It includes $114 million in 2009, $100 million in 2010 and $90 million annually in years 2011-2013 for non-interstate pavement preservation. It includes $38 million annually in 2009 and 2010, and $35 million annually in years 2011-2013 for non-interstate bridges. In addition, $15 million annually is allocated for safety projects. However, due to increasing construction costs, flattened revenues and overall highway systems needs, the Commission acknowledges that insufficient funds are being invested in the maintenance and preservation of the existing highway system. Another objective involves investing in projects that have received funding from the federal transportation act and/or subsequent federal transportation appropriation acts. In particular, funding is being used where it will complete a project, corridor or useable segment of a larger project. As an investment goal, the Commission also wishes to advance highway projects that address the state's highway capacity and economic development needs. Projects that address these needs and were included for completion in the previous program have been advanced into this year's Program to maintain their scheduled completion. This program also includes a small number of other projects that generally either represent a final phase of a partially programmed project or an additional segment of a partially completed corridor. The TIME-21 bill, Senate File 2420, signed by Governor Chet Culver on April 22, provides additional funding to cities, counties and the Iowa DOT for road improvements. This will result in additional revenue to the Primary Road Fund beginning in the second half of FY2009 and gradually increase over time. The additional funding will be included in future highway programming objectives and proposals and is not reflected in this highway program. The Iowa DOT and Commission appreciate the public's involvement in the state's transportation planning process. Comments received personally, by letter, or through participation in the Commission's regular meetings or public input meetings held around the state each year are invaluable in providing guidance for the future of Iowa's transportation system. It should be noted that this document is a planning guide. It does not represent a binding commitment or obligation of the Commission or Iowa DOT, and is subject to change. You are invited to visit the Iowa DOT's Web site at iowadot.gov for additional and regular updates about the department's programs and activities.

2010- 2014 Iowa Transportation Improvement Program

The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state’s transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. A major component of the 2010-2014 Program is the full integration of funding allocated to the Iowa DOT from the American Recovery and Reinvestment Act of 2009 (Recovery Act). To date, the Recovery Act has provided over $400 million of additional federal funding for transportation in Iowa, including funding that is allocated to local governments and entities. Recovery Act funding will result in a record year for transportation construction in Iowa and the creation and retention of jobs. Opportunities for additionalRecovery Act transportation funding remain and will be pursued as they becomeavailable. While Recovery Act funding will make a one-time significant impact in addressing Iowa’s backlog of needs, it is important to note that there remains a large shortfall in sustained annual transportation investment to meet Iowa’s current and future critical transportation needs. In recognition of this shortfall, Governor Culver introduced and the legislature passed an I-JOBS proposal. I-JOBS will result in an additional $50 million of state funding to reduce structurally deficient and functionally obsolete bridges on the primary road system and approximately $10 million in funding for other modes of transportation including $3 million of new funding to support the expansion of passenger rail service in Iowa. I-JOBS, and the continuing gradual increase in funding due to TIME-21, will complement and extend the benefits of Recovery Act funding and set the stage for addressing the shortfall in annual funding in the next few years. Iowa’s transportation system is multi-modal; therefore, the Program encompasses investments in aviation, transit, railroads, trails, and highways. A major component of the Program is the highway section. The FY2010-2014 highway section is financially balanced and was developed to achieve several objectives. The Commission’s primary highway investment objective is stewardship (i.e. safety, maintenance and preservation) of Iowa’s existing highway system. The highway section includes an annual average of $104 million for preserving the interstate system; an annual average of $78 million for non-interstate pavement preservation; an annual average of $36 million for non-interstate bridges; and an annual average of $14 million for safety projects. Another objective is to maintain the scheduled completion of interstate and non-interstate capacity and economic development projects that were identified in the previous Program and this Program does so. The final Commission objective is to further address capacity and economic development needs and the Commission has done so by adding several such projects to the Program. Construction improvements are partially funded through the current federal transportation act, Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). The act will expire September 30, 2009. With the expiration of SAFETEA-LU, there is significant uncertainty in the forecast of federal revenues in the out-years of this Program. The Commission and Iowa DOT will monitor federal actions closely and make adjustments to the Program as necessary. The Iowa DOT and Commission appreciate the public’s involvement in the state’s transportation planning process. Comments received personally, by letter, or through participation in the Commission’s regular meetings or public input meetings held around the state each year are invaluable in providing guidance for the future of Iowa’s transportation system. It should be noted that this document is a planning guide. It does not represent a binding commitment or obligation of the Commission or Iowa DOT, and is subject to change. You are invited to visit the Iowa DOT’s Web site at iowadot.gov for additional and regular updates about the department’s programs and activities.

2011 - 2015 Iowa Transportation Improvement Program

The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state’s transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. This document serves as the Iowa DOT's annual report as required by Iowa Code section 7A.9. This document reflects Iowa’s multimodal transportation system by the inclusion of investments in aviation, transit, railroads, trails, and highways. A major component of this program is the highway section that documents programmed investments on the primary highway system for the next five years. A large part of funding available for highway programming comes from the federal government. Accurately estimating future funding levels of this federal funding is dependent on having a current enacted multi-year federal transportation authorization. The most recent authorization, Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), expired September 30, 2009, and to date it has been extended five times because a new authorization has not yet been enacted. The current extension expires December 31, 2010. While Iowa law does not require the adoption of a Program when federal transportation funding is being reauthorized, the Commission believes it is important to adopt a Program in order to continue on-going planning and project development efforts and to be well positioned when a new authorization is adopted. However, it is important to recognize that, absent a federal authorization bill, there is significant uncertainty in the forecast of federal revenues. The Commission and the Iowa DOT will continue to monitor federal revenues and will adjust future investments as needed to maintain a fiscally responsible Program. In developing the highway section of the program, the Commission’s primary investment objective remains stewardship (i.e. safety, maintenance and preservation) of Iowa’s existing highway system. In fact, over $1.2 billion is programmed in FY2011 through FY2015 for preservation of Iowa’s existing highway system and for enhanced highway safety features. The highway section also includes significant investments for interstate modernization on I-29 inSioux City, on I-29/80/480 in Council Bluffs, and on I-74 in Bettendorf/ Davenport. Another highway programming objective reflected in this Program is maintaining the scheduled completion of capacity and economic development projects that were identified in the previous Program. Finally, with the limited remaining funds the Commission has furthered the investment in capacity and economic development by adding a few projects to the Program. The Iowa DOT and Commission appreciate the public’s involvement in the state’s transportation planning process. Comments received personally, by letter or through participation in the Commission’s regular meetings or public input meetings held around the state each year, are invaluable in providing guidance for the future of Iowa’s transportation system.

2012-2016 Iowa Transportation Improvement Program

The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state’s transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. This document reflects Iowa’s multimodal transportation system by the inclusion of investments in aviation, transit, railroads, trails, and highways. A major component of this program is the highway section that documents programmed investments on the primary highway system for the next five years. 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 current enacted multi-year federal transportation authorization. The most recent authorization, Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), expired September 30, 2009, and to date it has been extended seven times because a new authorization has not yet been enacted. The current extension will expire September 30, 2011. This leads to significant uncertainty in federal funding; however, it is becoming evident that, in Federal Fiscal Year 2012 and beyond, federal funding revenue will likely be reduced by 25 percent from current levels in order to match revenue that flows into the Highway Trust Fund. This Program reflects this anticipated reduction in federal funding. While Iowa law does not require the adoption of a Program when federal transportation funding is being reauthorized, the Commission believes it is important to adopt a Program in order to continue on-going planning and project development efforts so that Iowa will be well positioned when a new authorization is adopted. However, it is important to recognize that, absent a federal authorization bill, there is significant uncertainty in the forecast of federal revenues. The Commission and the Iowa DOT will continue to monitor federal revenues and will adjust future investments as needed to maintain a fiscally responsible Program. For 2012-2016, approximately $2.3 billion is forecast to be available for highway right of way and construction. In developing the highway section of the Program, the Commission’s primary investment objective remains stewardship (i.e. safety, maintenance and preservation) of Iowa’s existing highway system. Over $1.3 billion is programmed in FY2012 through FY2016 for preservation of Iowa’s existing highway system and for enhanced highway safety features. The highway section also includes significant interstate investments on I-29 in Sioux City, I-29/80/480 in Council Bluffs, and I-74 in Bettendorf/Davenport. The FY2016 programming for construction on I-74 in Bettendorf/Davenport is the first of several years of significant investments that will be monitored for available funding. Approximately $200 million of the investments on these three major urban interstate projects address preservation needs. In total, approximately $1.5 billion is programmed for highway preservation activities for 2012- 2016. Another highway programming objective is maintaining the scheduled completion of capacity and economic development projects. Projects that were previously scheduled to be completed within the previous Program continue on their current schedule. However, due to the reduction of projected federal revenues, the Commission has delayed by one year the initiation of construction of all multi-year non-Interstate capacity and economic development projects that cannot be completed within this Program. These projects are U.S. 20 in Woodbury County, U.S. 30 in Benton County, U.S. 61 in Louisa County, and Iowa 100 in Linn County. The Iowa DOT and Commission appreciate the public’s involvement in the state’s transportation planning process. Comments received personally, by letter or through participation in the Commission’s regular meetings or public input meetings held around the state each year, are invaluable in providing guidance for the future of Iowa’s transportation system. It should be noted that this document is a planning guide. It does not represent a binding commitment or obligation of the Commission or Iowa DOT, and is subject to change.

Highway Program Summary, 2012 to 2016

The Iowa Transportation Commission (Commission) and the Iowa Department of Transportation (Iowa DOT) develop Iowa’s Five Year Highway Program to inform Iowans of planned investments in our state’s primary highway system. This brochure summarizes the 2012-2016 Iowa Highway Program (Program) and provides information about long-term highway programming issues, through the year 2020. The Program is typically updated and approved each year in June.

2009 Iowa’s Rail System Background Prepared by the Office of Systems Planning December 2010

Iowa’s Rail Environment Iowa’s rail transportation system provides both freight and passenger service. Rail serves a variety of trips, including those within Iowa and those to other states as well as to foreign markets. While rail competes with other modes, it also cooperates with those modes to provide intermodal services to Iowans. In 2009 Iowa’s rail transportation system could be described as follows: Freight Iowa’s 130,000-mile freight transportation system includes an extensive railroad network, a well-developed highway system, two bordering navigable waterways, and a pipeline network as well as air cargo facilities. While rail accounts for only 3 percent of the freight network, it carries 43 percent of Iowa’s freight tonnage. A great variety of commodities ranging from fresh fish to textiles to optical products are moved by rail. However, most of the Iowa rail shipments consist of bulk commodities, including grain, grain products, coal, ethanol, and fertilizers. The railroad network performs an important role in moving bulk commodities produced and consumed in the state to local processors, livestock feeders, river terminals and ports for foreign export. The railroad’s ability to haul large volumes, long distances at low costs will continue to be a major factor in moving freight and improving the economy of Iowa. Key 2008 Facts • 3,945 miles of track • 18 railroads • 49.5 million tons shipped • 39.7 million tons received • 2 Amtrak routes • 6 Amtrak stations • 66,286 rail passenger rides Key Rail Trends • slightly fewer miles being operated; • railroads serving Iowa has remained the same; • more rail freight traffic; • more tons hauled per car; • higher average rail rates per ton-mile since 2002; • more car and tons hauled per locomotive; and • more ton miles per gallon of fuel consumed. Iowa’s rail system and service has been evolving over time relative to its size, financial conditions, and competition from other modes.

Iowa Highway Research Board TR-423: 1949–1999, 1999

The year 1949 saw the Iowa General Assembly’s establishment of the Iowa Secondary Road Research Fund, which led to the creation of a supervisory board within what was then the Iowa State Highway Commission to oversee the expenditure of that fund. The purpose of the fund and the board was to research road construction topics likely to be beneficial to the working of Iowa’s secondary, or local, road system. The supervisory board—called the Iowa Highway Research Board (the “Board”)—was organized by the highway commission in December 1949 and first met in May 1950. The creation of the fund and of the Iowa Highway Research Board marked the first organized effort in the United States to investigate local road construction problems and placed Iowa in the forefront of this field of engineering research. That Iowa should be a leader in such an effort is not surprising, given the early and sustained emphasis of the Iowa State Highway Commission on both research and the dissemination of information to county authorities. Now, 50 years later, a retrospective is in order. To that end, the Iowa Highway Research Board commissioned the preparation of a commemorative history. This work is the result of that project. Throughout its existence, the Board has funded nearly 450 projects, several of national significance. Many new construction and maintenance techniques have been developed, some of which have evolved into standard practices in highway construction. Innovative new materials and equipment have been tested. Still other projects have considered a wide variety of subjects related to the efficient operation of the highway system. Highway safety, conservation, and law have all come under research scrutiny. While it will not be possible, given the short space available, to consider all the projects financed by the Iowa Highway Research Board, it is well worthwhile to examine the Board’s principal projects and its resulting contributions to the field of highway research.

Missouri River Flood Coordination Task Force Report, September 25, 2011

The Missouri River floods of 2011 will go down in history as the longest duration flooding event this state has seen to date. The combination of above normal snowfall in the upper Missouri River basin followed by the equivalent of nearly one year’s worth of rainfall in May created an above normal runoff situation which filled the Missouri River and the six main reservoirs within the basin. Compounding this problem was colder than normal temperatures which kept much of the snowpack in the upper basin on the ground longer into the spring, setting the stage for this historic event. The U.S. Army Corps of Engineers (USACE) began increasing the outflow at Gavin’s Point, near Yankton, South Dakota in May. On June 14, 2011, the outflow reached a record rate of over 160,000 cubic feet per second (cfs), over twice the previous record outflow set in 1997. This increased output from Gavin’s Point caused the Missouri River to flow out of its banks covering over 283,000 acres of land in Iowa, forcing hundreds of evacuations, damaging 255,000 acres of cropland and significantly impacting the levee system on the Missouri River basin. Over the course of the summer, approximately 64 miles of primary roads closed due to Missouri River flooding, including 54 miles of Interstate Highway. Many county secondary roads were closed by high water or overburdened due to the numerous detours and road closures in this area. As the Missouri River levels began to increase, municipalities and counties aided by State and Federal agencies began preparing for a sustained flood event. Citizens, businesses, state agencies, local governments and non‐profits made substantial preparations, in some cases expending millions of dollars on emergency protective measures to protect their facilities from the impending flood. Levee monitors detected weak spots in the levee system in all affected counties, with several levees being identified as at risk levees that could potentially fail. Of particular concern was the 28 miles of levees protecting Council Bluffs. Based on this concern, Council Bluffs prepared an evacuation plan for the approximately 30,000 residents that resided in the protected area. On May 25, 2011, Governor Branstad directed the execution of the Iowa Emergency Response Plan in accordance with Section 401 of the Stafford Act. On May 31, 2011, HSEMD Administrator, Brigadier General J. Derek Hill, formally requested the USACE to provide technical assistance and advanced measures for the communities along the Missouri River basin. On June 2, 2011 Governor Branstad issued a State of Iowa Proclamation of Disaster Emergency for Fremont, Harrison, Mills, Monona, Pottawattamie, and Woodbury counties. The length of this flood event created a unique set of challenges for Federal, State and local entities. In many cases, these organizations were conducting response and recovery operations simultaneously. Due to the length of this entire event, the State Emergency Operations Center and the local Emergency Operations Centers remained open for an extended period of time, putting additional strain on many organizations and resources. In response to this disaster, Governor Branstad created the Missouri River Recovery Coordination Task Force to oversee the State’s recovery efforts. The Governor announced the creation of this Task Force on October 17, 2011 and appointed Brigadier General J. Derek Hill, HSEMD Administrator as the chairman. This Task Force would be a temporary group of State agency representatives and interested stakeholders brought together to support the recovery efforts of the Iowa communities impacted by the Missouri River Flood. Collectively, this group would analyze and share damage assessment data, coordinate assistance across various stakeholders, monitor progress, capture best practices and identify lessons learned.

Pavement Management Performance Modeling: Evaluating the Existing PCI Equations, RB14-013 2014

The work described in this report documents the activities performed for the evaluation, development, and enhancement of the Iowa Department of Transportation (DOT) pavement condition information as part of their pavement management system operation. The study covers all of the Iowa DOT’s interstate and primary National Highway System (NHS) and non-NHS system. A new pavement condition rating system that provides a consistent, unified approach in rating pavements in Iowa is being proposed. The proposed 100-scale system is based on five individual indices derived from specific distress data and pavement properties, and an overall pavement condition index, PCI-2, that combines individual indices using weighting factors. The different indices cover cracking, ride, rutting, faulting, and friction. The Cracking Index is formed by combining cracking data (transverse, longitudinal, wheel-path, and alligator cracking indices). Ride, rutting, and faulting indices utilize the International Roughness Index (IRI), rut depth, and fault height, respectively.

Analysis of Safety Benefits for Shielding of Bridge Piers, 2009

The highway system in the State of Iowa includes many grade separation structures constructed to provide maximum safety and mobility to road users on intersecting roadways. However, these structures can present possible safety concerns for traffic passing underneath due to close proximity of piers and abutments. Shielding of these potential hazards has been a design consideration for many years. This study examines historical crash experience in the State of Iowa to address the advisability of shielding bridge piers and abutments as well as other structure support elements considering the offset from the traveled way. A survey of nine Midwestern states showed that six states had bridge pier shielding practices consistent with those in Iowa. Data used for the analyses include crash data (2001 to 2007) from the Iowa Department of Transportation (Iowa DOT), the Iowa DOT’s Geographic Information Management System (GIMS) structure and roadway data (2006) obtained from the Office of Transportation Data, and shielding and offset data for the bridges of interest. Additionally, original crash reports and the Iowa DOT video log were also utilized as needed. Grade-separated structures over high-speed, multilane divided Interstate and primary highways were selected for analysis, including 566 bridges over roadways with a speed limit of at least 45 mph. Bridges that met the criteria for inclusion in the study were identified for further analysis using crash data. The study also included economic analysis for possible shielding improvement.

Making a Modern Highway: Transformation of Iowa Roadways in the Mid-Twentieth Century, 2014

The booklet tells the history of the construction of the Iowa Highway 376 Bridge within the context of significant modernization and expansion of the highway system in Iowa in the 1950s. Curvy, narrow highways were widened and straightened and narrow iron truss bridges were replaced with more modern concrete and steel structures, changing the landscape of rural Iowa. Bridge engineer Herbert A Arthur, who designed the Iowa Highway 376 Bridge, was a prolific bridge engineer in the 1950s. This booklet serves to inform the public of this significant aspect of Iowa transportation history.

Total Cost of Transportation Analysis of Road and Highway Issues, HR-388, 2002

In the administration, planning, design, and maintenance of road systems, transportation professionals often need to choose between alternatives, justify decisions, evaluate tradeoffs, determine how much to spend, set priorities, assess how well the network meets traveler needs, and communicate the basis for their actions to others. A variety of technical guidelines, tools, and methods have been developed to help with these activities. Such work aids include design criteria guidelines, design exception analysis methods, needs studies, revenue allocation schemes, regional planning guides, designation of minimum standards, sufficiency ratings, management systems, point based systems to determine eligibility for paving, functional classification, and bridge ratings. While such tools play valuable roles, they also manifest a number of deficiencies and are poorly integrated. Design guides tell what solutions MAY be used, they aren't oriented towards helping find which one SHOULD be used. Design exception methods help justify deviation from design guide requirements but omit consideration of important factors. Resource distribution is too often based on dividing up what's available rather than helping determine how much should be spent. Point systems serve well as procedural tools but are employed primarily to justify decisions that have already been made. In addition, the tools aren't very scalable: a system level method of analysis seldom works at the project level and vice versa. In conjunction with the issues cited above, the operation and financing of the road and highway system is often the subject of criticisms that raise fundamental questions: What is the best way to determine how much money should be spent on a city or a county's road network? Is the size and quality of the rural road system appropriate? Is too much or too little money spent on road work? What parts of the system should be upgraded and in what sequence? Do truckers receive a hidden subsidy from other motorists? Do transportation professions evaluate road situations from too narrow of a perspective? In considering the issues and questions the author concluded that it would be of value if one could identify and develop a new method that would overcome the shortcomings of existing methods, be scalable, be capable of being understood by the general public, and utilize a broad viewpoint. After trying out a number of concepts, it appeared that a good approach would be to view the road network as a sub-component of a much larger system that also includes vehicles, people, goods-in-transit, and all the ancillary items needed to make the system function. Highway investment decisions could then be made on the basis of how they affect the total cost of operating the total system. A concept, named the "Total Cost of Transportation" method, was then developed and tested. The concept rests on four key principles: 1) that roads are but one sub-system of a much larger 'Road Based Transportation System', 2) that the size and activity level of the overall system are determined by market forces, 3) that the sum of everything expended, consumed, given up, or permanently reserved in building the system and generating the activity that results from the market forces represents the total cost of transportation, and 4) that the economic purpose of making road improvements is to minimize that total cost. To test the practical value of the theory, a special database and spreadsheet model of Iowa's county road network was developed. This involved creating a physical model to represent the size, characteristics, activity levels, and the rates at which the activities take place, developing a companion economic cost model, then using the two in tandem to explore a variety of issues. Ultimately, the theory and model proved capable of being used in full system, partial system, single segment, project, and general design guide levels of analysis. The method appeared to be capable of remedying many of the existing work method defects and to answer society's transportation questions from a new perspective.