Click for next page ( 18


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 17
17 A. CURRENT PRACTICES FOR RISK review their safety performance over time. The intent is MANAGEMENT not to second-guess a decision, but to build on and im- prove a knowledge base for future decisions regarding How much risk can the state accept? The risk analy- design exceptions. sis83 below may be helpful initially in evaluating design options and setting up a documented file. Once the de- B. CURRENT PRACTICES--DOCUMENTATION OF cision has been made to balance safety against other THE DESIGN ANALYSIS factors such as cost and environmental impact, it will be necessary to periodically evaluate projects and roads to determine whether the tradeoff was worth the risk 1. Statutes of Limitation and Records Retention taken. For instance, when the community requests that In most states, statutes of limitation do not exceed 5 a large beautiful tree be left in place, if that tree is re- years for personal injury or wrongful death claims, and peatedly struck even though mitigation steps such as the agency does not necessarily keep documentation of rumble strips or barriers were used, the tree may need accident scenes or work diaries for more than the statu- to be removed or the protection enhanced. A system tory period. When planning to defend a design claim, it should be set up that will evaluate the mitigation is important to remember that the agency may have to strategies that were used to ensure that they are effec- defend a road or road design that has been in place tive. Periodic safety studies or accident studies could years or even decades. For that reason, counsel must also be done to ensure adequate performance of the de- ensure that the agency has a records retention policy in sign features. place that ensures important design documentation is kept and accessible even though technology may Consider Multiple Alternatives. Thorough consid- change. eration of alternatives, including an explanation as to the reasons a full standard design may not be possible 2. Documentation of the Deviation from Standards or desirable, and what alternatives exist, represent Process good risk management practices. Each responding agency indicated that it had a for- Evaluate and Document Design Decisions. Design mal design exception process and provided copies of or reports should document the expected operational and Internet links to that process. Most agencies use a let- safety performance of the proposal. Stakeholder en- ter format with an analysis of each pertinent part, i.e., gagement, including developing, evaluating, and dis- the purpose of the project, the type of exception re- cussing different alternatives, requires documentation. quested, the purpose of the exception, and the expected All documentation can and should be readily available benefits of the exception. to place in project files for later reference. Special care Survey Results.--Questions such as "What documen- should be taken where a new or creative concept is pro- tation process is used by the agency for documenting posed such as a roundabout or traffic calming feature. If decisions that deviate from the generally accepted a design exception is needed, documentation should be guidelines?" and "What documentation is developed complete, including a full description of the need for the while the project is being scoped and designed?" were exception based on adverse effects on community val- asked in the survey. In response, most agencies at- ues, the environment, and any other pertinent factors. tached forms that they used or links to a process they Maintain Control Over Design Decision-Making. used, typically found in their design manuals. For ex- The agency must stay in control of decisions regarding ample, Delaware requires an analysis of the following basic design features or elements. Active stakeholder factors in its design documentation file: involvement and input does not translate to abrogation of the responsibility of the agency to make fundamental Existing roadway characteristics. design decisions. Analysis of required versus proposed design crite- Demonstrate a Commitment to Mitigate Safety ria. Concerns. Where a design exception or unusual solution Comparison of required versus proposed cross sec- is proposed, plan completion should focus on mitigation. tions. Decisions to maintain trees along the roadside, for ex- Supporting calculations/analysis. ample, may be accompanied by special efforts to deline- Analysis of the effect of the project on new and pro- ate the edge line and trees, implement shoulder rumble posed right-of-way. strips, or provide a guardrail or other roadside barriers. Environmental effect. Monitor Design Exceptions to Improve Decision- Analysis of proposed mitigation steps and how the Making. A few states make a special effort to keep a steps offset the variance. record of design exceptions by location, committing to Costs of mitigation. The support or opposition of the public to the pro- 83 See TIMOTHY NEUMAN, MARCY SCHWARTZ, ET AL. NCHRP posal. 480: A GUIDE TO BEST PRACTICES FOR ACHIEVING CONTEXT SENSITIVE SOLUTIONS 51 (2002), http://contextsensitive Generally, the agencies responded that their proc- solutions.org/content/reading/nchrp-report/. esses consisted of several layers of review that must

OCR for page 17
18 occur before a variance to generally-accepted standards recommended practices in typical situations. Deviations is presented to the chief engineer or his or her counter- from the criteria denoted as guidelines are allowed part. In Connecticut, the layers of review include when engineering judgment or study85 indicates the evaluation by the initial design squad; then review by a deviation to be appropriate. Adequate study, justifica- core team that consists of professionals from design, tion, and documentation by the GDOT office or consult- right-of-way, construction, and maintenance; and only ant responsible for the engineering are required when a then a review by a management team. deviation to a guideline is proposed. In Florida, as in most states, several alternatives are Iowa Design Manual.--Excerpts from Iowa's design considered before the agency chooses a "preferred" de- manual can be found in Appendices D and E. The sec- sign. The following engineering information is gathered, tions deal directly with selecting and documenting de- and an evaluation matrix is prepared for each alterna- sign criteria. "Working Within Constraints" describes tive: the financial constraints most state transportation agencies are currently facing. Iowa recognizes that, to Conceptual design plans. do a project, the road may need to be designed using Survey information. values that are below preferred design criteria simply Analysis of existing conditions. to meet budgetary concerns. Under that scenario, seri- Analysis of safety issues. ous consideration is given to variables such as the type Typical sections, drainage, and floodplains. of road, the degree of variance from the recommended Maintenance issues. values, the effect of the variance on the safety and op- Estimated right-of-way and construction costs. eration of the facility, and whether mitigating features can offset the issues that could be caused by a deviation Several comprehensive forms used by the agencies to from the design standard. Safety is clearly a high prior- select or document their decision-making processes are ity, as the following statement is found in the policy: included as Appendices D (Iowa), E (Iowa), F (Dela- "[s]afety repairs should be addressed whenever possi- ware), and G (Tennessee). ble. Expecting safety repairs to be included in future resurfacing projects can lead to a steady degrading of 3. Specific State Examples of Procedures the highway system as repairs are continually delayed." The Georgia Department of Transportation (GDOT) The policy aids the agency in defending design claims uses the definitions and processes listed below when because it demonstrates that safety is a high priority in evaluating and analyzing its proposed designs.84 These the project selection and design process but also recog- definitions are helpful when defending claims for the nizes that real economic constraints must be considered agency because they illustrate that much thought and during the design phase. These excerpts should assist debate occurs before a design exception can be ap- the agency in explaining that it balanced the factors proved. The definitions illustrate the importance of noted above, and the "whenever possible" language is choosing the best design solution to a design problem loose enough to allow the agency to exercise its engi- and that the agency emphasizes the importance of en- neering judgment in determining when safety repairs gineers applying "engineering judgment." should be addressed. Delaware Design Manual.--Excerpts from Dela- Standards: A standard is a required criteria or ware's design manual can be found in Appendix F. The mandatory practice. Criteria denoted as standards have section instructs staff how to determine when a "depar- been identified by the Department as having substan- ture from standards" is necessary and how to document tial importance to the operational and safety perform- that decision effectively. The forms are used to docu- ance of a roadway such that special agency review and ment decisions on design criteria, but it is expected that approval (Design Variance or Design Exception) will be the primary focus of the exception request should be required before deviation from the controls can be in- highway safety. The documentation that is required corporated into a design. The approval of a Design Variance from the GDOT Chief Engineer is required to 85 "Engineering Judgment" is defined by the MUTCD as document a decision to deviate from GDOT criteria that "the evaluation of available pertinent information and the ap- has been identified as "standard" before the design ele- plication of appropriate principles, provisions contained in this ment or feature can be retained or incorporated into a manual and other sources, for the purpose of deciding upon the project. The approval of a Design Exception from the applicability, design, cooperation, or installation of a traffic GDOT Chief Engineer is required to document a deci- control device." MUTCD 14 (2009 edition). Engineering study is defined in the 2009 MUTCD as sion to deviate from AASHTO criteria that FHWA has identified as "controlling criteria" before the design the comprehensive analysis and evaluation of available perti- nent information, and the application of appropriate principles, element or feature can be retained or incorporated into provisions, and practices as contained in this Manual and other a project. sources, for the purpose of deciding upon the applicability, de- Guidelines: Guidelines suggest normal practice sign, operation, or installation of a traffic control device. An en- with options and advisory conditions. Guidelines are gineering study shall be performed by an engineer, or by an in- dividual working under the supervision of an engineer, through the application of procedures and criteria established by an en- 84 Survey response, Georgia DOT, May 2011. gineer. An engineering study shall be documented.

OCR for page 17
19 will be helpful to the agency facing a design defect alle- be represented for projects that require full FHWA over- gation because it addresses such issues as public input, sight.86 environmental effects, and cost, illustrating that the Recommendations and lessons learned from state agency considered the pros and cons of each of its deci- documentation. A lawsuit based upon an alleged "dan- sions prior to implementing any of them. gerous condition" of a roadway due to a design defect Tennessee's Design Exception and Justification form will necessarily contain allegations of the agency's fail- is included in Appendix G as an example of a form that ure to comply with generally-accepted standards and requires multiple narrative responses that leave room engineering principles. However, according to the text for analysis of factors such as "long-term effect" of the of the current standards and guidelines, those stan- reduced design, "difficulty obtaining the full standard," dards and guidelines are now flexible. The books con- and "safety mitigation measures considered." Staff can tain words such as "ranges" of acceptable values and then determine whether the measures taken can be "engineering judgment." The agency that based its de- justified or whether there is a true effect on the facility. sign on flexible design principles must be able to sup- Connecticut has the following procedures: The de- port the design by explaining that, even though recom- signer will not request an exception to controlling de- mended values were not necessarily achieved, the sign criteria until he or she has evaluated the impacts project as a whole was designed and constructed accord- of providing the minimum or better design values. If ing to the values of the community and the carefully these impacts are judged to be unacceptable, then the considered policy of the agency's governing authority. designer can initiate the exception process. The de- It is important to document all the public input and signer's goal will be to identify and seek approval of context-related information that is gathered and used design exceptions as early in the final design phase as in determining the design of the road. If the agency has practical. This procedure is included in this digest be- adopted a formal policy that requires or suggests the cause it illustrates a thorough process that identifies all use of the balancing factors process, and in fact that the "balancing factors" that are considered by the process is used to support a decision to leave a histori- agency and requires a discussion of each of those factors cal landmark or large tree in place or to widen lanes that are important. rather than add a lane, the basis of those decisions must be documented. That documentation in particular The following establishes the procedures the high- will be critical to the defense of a case when it is alleged way designer should follow for all proposed exceptions that plaintiff was injured due to inadequate mitigation to the department's established design criteria: measures being taken by the agency. Discussion of the following topics in the project docu- 1. The designers should present information to demon- mentation could be used: strate the impacts of meeting the minimum or lower de- sign criteria. This can include but is not limited to: What are the most important reasons for this pro- a. Construction costs, ject? How was community input on historical, safety, b. Environmental consequences, mobility, and environmental aspects gathered and ad- c. Right of way impacts, and dressed? Will the project as designed be durable and eco- d. Community involvement/concerns. nomical to maintain? 2. The designer should provide sufficient information to Does the project incorporate community develop- demonstrate the consequences of using a design value ment plans? that does not meet the minimum criteria. Where appro- How does the project address sites listed on the priate, this may include but is not limited to: state or national historic register? How was access for bicycle and pedestrian trans- a. Impacts on traffic serviceability (i.e., level of service), portation addressed? b. Impacts on safety (i.e., crash history), How was access to culturally significant sites ad- c. Impacts on traffic operations, and dressed? d. Impacts on future maintenance. Each of the above-noted procedures is useful in de- 3. The designer should prepare a written summary of the veloping or reworking documentation processes. The information and submit it to the appropriate Division policies indicate the importance of the initial public Manager for review. input process and the value of working with the public to determine what goals they want to achieve. Each 4. The designer will then arrange a meeting through the agency has a process in place where public input is office of the Engineering Administrator to discuss all pro- posed design exceptions. The Engineering Administrator, studied and the best design, based on the economic, Division Manager, and the Project Manager and/or Engi- historical, environmental, and safety factors involved. neer will usually attend the meeting. The FHWA will also 86 http://www.ct.gov/dot/lib/dot/documents/dpublications/ highway/cover.pdf.