Practical Highway Design Solutions (2013)

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31 Findings states That Have a Practical design Policy Of the 41 states that responded to a survey questionnaire, six were identified as having an explicit Practical Design policy. Missouri, Oregon, and Utah use the term Practical Design, Kentucky and Idaho the term Practical Solutions, and Kansas the term Practical Improvements. Each of these states has a formal policy and has published guidelines, to varying degrees of specificity as to how Practical Design (using this label for all three types) is to be applied in developing projects. Another 23 states reported that they have a policy or program similar to Practical Design, citing such terms as design flexibility, con- text sensitive solutions (CSS), smart transportation, design exceptions, value engineering (VE), and their resurfacing, res- toration, and rehabilitation program. How states define and implement Practical design None of the six states that have a Practical Design-type pol- icy have an explicit definition for the term they use; rather, they define their policy in terms of goals, tenets, principles, and process. The definitions provided here were composed from either statements made by each state or from the goals of the state’s Practical Design, Solutions, or Improvements policy documents: • Missouri—Practical Design is an approach to transpor- tation where the value of an individual project is maxi- mized within the context of its surroundings, such that it contributes to the entire system instead of its individual perfection. • Idaho—Practical Solutions is a project development process whereby the project is defined to meet the pur- pose and need through a cost-effective design, consider- ing life-cycle costs, and in consideration of the context of the surroundings. • Kentucky—Practical Solutions is a project development process from planning through operations and mainte- nance that examines a range of approaches and deter- mines which solution meets the purpose and need with the least cost. • Kansas—Practical Improvements is an overarching phi- losophy that guides project development decisions that affect project cost and scope in order to stretch transpor- tation improvement dollars further while still maintain- ing a safe and efficient highway system. • Oregon—Practical Design is a systematic approach to deliver the broadest benefits to the transportation sys- tem, within existing resources, by establishing appro- priate project scopes that meet the purpose and need and are within the system context. • Utah—Practical Design is a project development approach that focuses on maximizing improvements to the roadway system as a whole, rather than maximizing improvements to a few locations, by building a series of good, not great, projects. Rather than try to define either of these practical labels, it is appropriate to describe each through its tenets or prin- ciples. Although some minor variations exist among the pro- filed states, the basic tenets or principles of practical design/ solutions/improvements can be summarized as follows: • The goal of Practical Design is to build many “good” projects, rather than fewer “great” projects, to maximize system-wide safety and capacity improvements • The design of a project is based on addressing its stated objective—purpose and need—and not necessarily pro- viding more than that. The goal is to satisfy the proj- ect’s objective in the most cost-effective manner. • Practical Design does not eliminate the state engineer- ing standards; rather, it promotes flexibility needed to produce the most efficient design to meet the system and project objective statements. • Practical Design is a “design up” approach. It starts with the current conditions (if it is an existing facility) and builds up the improvements to meet the project objectives. • Practical Design requires designers to follow engineer- ing judgment in making decisions about design ele- ments rather than unquestioned application of design standards. Barriers and Lessons Learned from states That Have implemented Practical design None of the states voiced any significant barriers that were not overcome through training, education, and communica- tion among the stakeholders. State legislatures embraced the program as a practical way to achieve improvement projects chapter five Findings, ConCLusions, and suggesTed ReseaRCH

32 across the state within limited budgets. Some of the states interviewed acknowledged initial concerns by staff when Practical Design was first introduced to them, primarily because of not always using the higher level of design values for projects. These concerns were assuaged with training and instruction on the applying of engineering judgment to meet the projects purpose and need. Acceptance of the policy grew as it was shown that savings from individual projects with good design features could be used for more projects on the system. How Practical design differs from the Traditional design Process The “traditional” design process applies to Practical Design in that the same project development steps are followed and the state’s road design manual is used as a basis for design. What differs, or is more emphasized, is the proper scop- ing of each project at the planning level to satisfy the pur- pose and need, and then alternative designs are evaluated to achieve that scope at the least cost while improving safety and operations. The focus of Practical Design is on cost reduction for indi- vidual projects so that the savings can be used on additional projects. Therefore, its application may result in “downsizing” a project or, as some states, state “right-sizing.” From the six state profile discussions this can mean: • Scoping a project based on a shorter design year; for example, 10 year versus 20 year, consistent with a proj- ect’s unique needs. • Scoping a project based on a lower level of service (LOS); for example, LOS D versus LOS C. • Selecting a design speed equal to the current posted speed limit, which in turn affects the selection of some design element values. • Selecting a specific design element, such as shoulder width, different than would be required under the state’s design manual. • Customizing the pavement thickness or using different pavement material as appropriate based on the under- lying soil. Modifications to Roadway geometric design Criteria For all six states, the geometric design criteria in their road design manuals still apply and serve as the basis for design with modifications, through design exceptions or variances, made as needed to meet the projects purpose and need. Only two states—Missouri and Kentucky—supply specific modifi- cations to their geometric design criteria. Missouri’s Practical Design Implementation Manual provides general guidance on selecting design elements as shown in Appendix C. In Appendix F, accompanying Kentucky’s Practical Solutions memorandum, is a series of tables for the various functional roadway classifications with design values for several ele- ments. These tables are meant to “provide guidance” and the flexibility needed to adapt critical design elements to be con- sistent with the purpose and need for the project. Relationship of Practical design to Context sensitive solutions, Value engineering, and other similar initiatives As described in chapter three, CSS seeks a solution that addresses the needs of multiple users and functions of the facil- ity within the context of its setting considering land use, users, the environment, and other factors. Another key element of CSS is interaction and communication with all stakeholders— local governments, citizens, elected officials, etc.—to achieve an acceptable solution. The hallmark of Practical Design is developing a project that satisfies the purpose and need and fits within the project limit context, which is a similar goal for CSS. However, in applying Practical Design, cost, in terms of cost-effectiveness and rate-of-return, becomes a critical driver that could limit the project solution under CSS. The relationship of Practical Design to CSS was the focus of a paper by Stamatiadis and Hartman, “Context Sensi- tive Solutions vs. Practical Solutions: What are the Differ- ences?” The authors initially recognized the possible conflict between the two project development policies, but later noted that they can be in harmony. In discussing KYTC’s Practi- cal Solutions approach, it “. . . provides two improved CSS principles (relating to purpose and need and using agency resources effectively) and one new principle (regarding the system-wide context) to the extensive CSS attribute list.” The authors opine that “. . . if the Practical Solutions meth- odology is used completely in lieu of CSS, it would provide an excuse to ignore several important (and beneficial) CSS principles for project development and delivery.” Several of the states that did not have a Practical Design policy responded that their application of CSS policy could be considered Practical Design. For the six states that were profiled, most recognize a relationship and similarity in principles. For instance, Kansas reported that both CSS and Practical Design apply flexibility in the application of design features. Oregon views its Practical Design policy as the next logical step to CSS, a point that is made by Stamatiadis and Hartman. Utah views its Practical Solutions policy as com- bining elements of CSS and VE. Practical Design is not the same as VE, although here too there are similar goals. VE, which is usually reserved for large scale (more than $25 million) projects, is a method to determine the most cost-effective way to achieve proposed improvements. Practical Design is a method to determine the most cost-effective way to achieve the projects purpose and need. However, the tools and procedures used for VE can be

33 used for Practical Design. For the states interviewed, they see these two initiatives as being separate programs, but as noted Utah views its Practical Solutions as a combination of these two initiatives. Project-specific Roadway design Tradeoffs Considered The issue here was twofold—what types of design tradeoffs are considered and how are those tradeoffs evaluated. The case examples provided in chapter four and in the appen- dices indicate the types of tradeoffs considered, which, of course, vary by specific project. They include most of the pri- mary design elements, including cross-section widths, road- side features, and longitudinal alignment. Most of the states interviewed indicated that they examine the expected safety outcomes under the different alternatives in evaluating trad- eoffs. Several states indicated that they are starting to use the information and procedures contained in the Highway Safety Manual. application of design exceptions for Practical design The preparation of design exceptions is an important element when applying Practical Design. Each of the states profiled in chapter four reported that design exceptions or design variances are prepared when a value for a design element is chosen that is less than what would be required by its design manual. Cost savings Resulting from Practical design Projects Practical Design emerged out of the need to stretch available funding so that more improvement projects could be com- pleted within the fiscal budget. The several case examples in this report provide evidence of the cost savings attained, which for many projects was substantial. According to the states these savings were used for additional projects. The cost savings presented were construction costs and not life- cycle costs, which could not be established until the projects reached their design life. Liability Risk of implementing Practical design approaches Specific data on the incidences of tort liability claimed against Practical Design was not collected nor sought from the states interviewed. However, none of the states inter- viewed indicated that this was a concern for senior level management. In fact, two states indicated that they believed they would have less risk, because they would be applying engineering judgment supported by adequate documentation of their rationale. ConCLusions All state transportation agencies have project needs that exceed their available funds and are seeking project development solu- tions that optimize these funds for their entire system. Practi- cal Design/Solutions/Improvements is an emerging project development paradigm that has been adopted as a policy by only a few, specifically six, states as of this synthesis prepara- tion. A few states are either in the process of adopting a policy or considering doing so. Still other states believe that they are following Practical Design principles through similar initia- tives including CSS, Smart Transportation, flexible design, design exceptions, and VE. The six states that have a formal policy are not using the same label; however, they have a common goal—developing individual projects cost-effectively to meet only the project’s purpose and need and applying cost savings for additional projects, thereby optimizing their budgets statewide. This typ- ically results in individual projects being downsized in various ways, including shorter design year, attaining a lower LOS, limiting the design speed and selecting lower design values for specific geometric design elements, structures, and pave- ments, commensurate with the project context. This project development paradigm has been shown to achieve the goal of implementing more improvement projects with available resources. Data to date, while not nearly robust enough to draw a conclusion, indicate that safety has not been com- promised. In Missouri, the first state to adopt it, Practical Design has been in operation for only seven years and for the other five states even less time. With more time, states will have more experience and data on how well the application of Practical Design is achieving its goal. suggesTed ReseaRCH There are two areas where research is suggested to support further development and application of Practical Design. 1. Practical Design is based on the premise that it is better for the entire system to develop several “good” proj- ects than a lower number of “higher designed” proj- ects within a fixed budget for system improvements. It is assumed that the entire transportation system is improved more so under this strategy than if the “stan- dard” approach was followed. This assumption has yet to be proven by either of the states that are applying Practical Design policies. The cost savings are well- documented; however, there has not been a compre- hensive evaluation by any of the states to determine if this assumption is valid. To do so would not be easy. What would be the per- formance measures? They would likely include safety, operations, and costs as a minimum. One would have

34 to assume how the performance measures would have changed without a Practical Design policy. Nonethe- less, some high-level, macroscopic evaluation of the Practical Design approach is recommended so that its efficacy can be established for future considerations. 2. The application of practical design frequently requires making choices among alternative design elements, especially some that are related to safety; that is, crash occurrence. For example, there may be a choice between having wide shoulders throughout the project limits versus reducing the severity of one or more horizon- tal curves. These types of tradeoff decisions are better made if it is known what the relationship is between either of these two design elements and safety. What will be the crash frequency and severity change for each alternative? Progress has been made in developing crash modification factors (CMFs) (see the CMF clearing- house at http://www.cmfclearinghouse.org/ for more information) for many design elements and traffic con- trol devices. These CMFs are continuously being devel- oped and updated for new elements and variations. This research needs to be continued so that the states know that the safety/design element relationships and can better evaluate alternatives.