Investment Prioritization Methods for Low-Volume Roads (2018)

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Case Examples 39 military facilities that provide intermodal access or support access to universities or recreational areas are given additional points (Table 13). Recent trends and interest in improvements. Arizona DOT reported increased attention paid to LVRs due to budgetary constraints and interest in determining whether LVRs should remain in the state highway system. The Arizona DOT Low Volume State Routes Study (2017) is the first step in this process. The study seeks to differentiate among low-volume roads, based on their overall significance to state or national transportation purposes: The State of Arizona has a number of low volume routes that are designated as State Highways. Some of these facilities do not warrant the State Highway designation because they do not serve a state or national purpose in the transportation system. . . . At the same time, there are other roadways that, despite low usage Maximum ScorePolicy Evaluation Criteria—Economic Drivers Economic Driver Access/Greater Arizona Primary Healthcare Facilities Score (10 mi) 3 Economic Driver Access/International Border Crossings Score (50 mi) 4 Economic Driver Access/Military Facilities Score (50 mi) 4 Economic Driver Access/Primary Train / Bus Station Score (10 mi) 4 Economic Driver Access/Primary Universities and Colleges Score (10 mi) 3 Economic Driver Access/Primary Airport Score (50 mi) 4 Economic Driver Access/Primary National Park/Recreation Area/State Park Score (50 mi) 4 Local Funding Contribution Score 5 Total Economic Driver Score 31 Policy Evaluation Criteria—Safety Safety - 100% HSIP Funded Score 5 HSIP Partial Funding Score 4 Safety - Identified Bicycle Safety Need 4 Safety - Bicycle Countermeasures Score 4 Safety - Identified Lane/Roadway Departure Safety Need Score 4 Safety - Lane/Roadway Departure Countermeasures Score 4 Safety - Identified Intersection Accident Safety Need Score 4 Safety - Intersection Accident Reduction Countermeasures Score 4 Safety - Identified Railroad Crossing Accident Safety Need Score 4 Safety - Railroad Crossing Accident Countermeasures Score 4 Safety - Identified Pedestrian Safety Need Score 4 Safety - Pedestrian Countermeasures Score 4 Total Safety Score 45 Policy Evaluation Criteria—Mobility Traffic Volume Score 3 Freight Flow Score 3 Supports Statewide Plans Score 3 Mobility/Functional Classification Score 3 Corridor Significance/Key Commerce Corridors Score 5 Corridor Significance/Strategic Corridors Score 4 Corridor Significance/National Highway System Score 3 Total Mobility Score 24 Combined Totals Total Mobility Score 24 Total Economic Driver Score 31 Total Safety Score 45 Total Policy Score Maximum Value 100 HSIP = highway safety improvement program; mi = miles. Source: Arizona DOT P2P Policy Evaluation Criteria (2015). Table 13. Arizona DOT planning to programming policy evaluation criteria (under refinement as of 2017).

40 Investment Prioritization Methods for Low-Volume Roads levels, are important to the State’s role in providing system-wide transportation connectivity. These should retain their State Highway standing, but may afford ADOT an opportunity to fine-tune maintenance and operations practices to be more in keeping with the level of usage on the roadway (page ES12). The criteria used to differentiate the routes include consideration of the markets served or access provided by the facilities, as shown in Figure 15. Routes that provide primary access of some sort or that are essential for regional system connectivity are more likely to be considered as warranting the state highway designation. However, other considerations also have a significant bearing on jurisdictional turn-back decisions. For example, one route that provides access to the Grand Canyon was identified as a high priority for removal from the state system despite its role in providing primary access to a national park. This is because the road lies entirely Source: Arizona DOT Low Volume State Routes Study (2017). Figure 15. Low-volume roadway characteristics.

Case Examples 41 within the Kaibab National Forest and thus is a candidate for route transfer to the Forest Service. Other routes may not be strong candidates for ownership transfer because they span multiple jurisdictions. While not directly part of the investment prioritization process, this planning study starts a process that may ultimately affect the allocation of resources within the state on LVRs. If an LVR was transferred from the state system to other owners, Arizona DOT would no longer program federal or state funds on those roads. Depending on eligibility, the receiving jurisdiction or agency could use other federal or distributed Arizona state resources (e.g., Highway User Revenue Fund) to maintain or reconstruct the roadway (Arizona DOT n.d.). For Arizona DOT, the next step in the planning process is engagement with stakeholders and coordination with partner agencies. 4.2.3 North Dakota: Low-Volume Roads and the Highway Performance Classification System Summary. North Dakota DOT does not designate a class of LVR defined by volumes. However, the agency recognizes that LVRs tend to fall within the lower three tiers of its five-tier HPCS. These tiers are defined through considerations that include road function, volume, design, speed, and public input. North Dakota DOT does not have a formal investment policy across HPCS levels but tends to allocate relatively fewer resources to lower classes of roads and sets different performance targets by class. The DOT’s process relies on engineering data from their asset management system to identify recommended improvements. These improvements are then prioritized by district engineers within an informal process that relies on qualitative local knowledge. It is this local knowledge, provided by the district engineer, which can elevate one LVR above another LVR, based on its strategic importance. In some cases, relative low-volume facilities may also be elevated to a higher HPCS class based on importance to specific communities or to system connectivity. North Dakota DOT is interested in new more quantitative methods that can be used to prioritize LVRs that serve locations disadvantaged by the level of existing network connectivity, or disadvantaged economically. The agency is also interested in improved consideration of freight in its prioritization process, including for LVRs, and cites data availability as a challenge. Definition of a low-volume road. North Dakota DOT divides its network into five classifi- cations of roadways, the lower three of which can be considered the equivalent of “low-volume roads,” from North Dakota DOT’s perspective (although this is, of course, not an absolute determination). This classification system is the Highway Performance Classification System and includes the following: (a) Interstate systems, (b) interregional systems, (c) state corridors, (d) dis- trict corridors, and (e) district collectors (North Dakota DOT 2016) (see Table 14). While Arizona DOT is involved in the definition of these five groups, North Dakota DOT also considers a variety of other types of information, including public input. Fifty to seventy percent of the entire net- work falls within the lower three classification levels. HPCS is reviewed in coordination with the update of the long-range transportation plan. Changes to the system, while relatively infrequent, can result from changes in observed conditions or from requests by stakeholders. Low-volume roads within the investment prioritization process. North Dakota DOT does not publish formal investment prioritization criteria or policies. However, the HPCS is used

42 Investment Prioritization Methods for Low-Volume Roads internally to define investment strategies. Projects are typically considered within three groups: (1) Interstates; (2) interregional routes; and (3) state corridors, district corridors, and district collectors combined. Investment strategy guidelines are to spend primarily on the Interstates and interregional systems, with the lower classes receiving less attention, in the same way that other agency’s “low-volume roads” might. Nevertheless, this is a strategy and not a strict prioritization within separate classes of roads. Consideration of critical strategic issues. The programming division of North Dakota DOT uses outputs from its asset management systems as well as inputs from individual districts to assemble the STIP. As part of that process, district engineers are given information on recom- mended projects from the asset management systems run by the central office. Recommendations from the asset management systems are based on quantitative analyses using decision trees and goals defined according to HPCS classes. District engineers then combine this information with qualitative local knowledge, ultimately assembling a list of priority requests to submit for pro- gramming by the central office. The use of local knowledge and the write-ups of individual priority projects by the district engineers are the points at which broader social, economic, or environmental factors are taken into account. For example, a district engineer might document how a project serves a new expanding grain elevator. Another way in which broader considerations related to LVRs are taken into account is through the HPCS definition process itself. There are cases in which relatively LVRs are nevertheless HPCS Level Summary Description Interstate System – Support international, national, regional, and statewide trade and economic activity through long-distance connections – High volumes, high truck percentages – Multiple lanes (typically four) with full access control – Speeds of 65 to 75 miles per hour Interregional System – Support international, national, regional, and statewide trade and economic activity through long-distance connections – Moderate to high volumes, high truck percentages – Two-lane or multiple lane facilities with partially controlled access in some locations – Speeds of 60 to 70 miles per hour State Corridor – Support the movement of agricultural commodities, freight, and manufactured products within the state though medium-distance connections; provide connectivity between lower and higher level roads – Moderately high volumes – Typically, two-lane facilities with partially controlled access in some locations – Speeds of 60 to 65 miles per hour District Corridor – Short- to medium-distance connections – Moderate volumes – Two-lane facilities generally without access control – Speeds of 55 to 65 miles per hour District Collector – Short routes that provide connectivity to higher level network; support local and farm-to-market traffic – Low volumes – Two-lane facilities without access control – Speeds of 50 to 55 miles per hour Source: Synthesized from North Dakota DOT Highway Performance Classification System—Five Levels (2016). Table 14. Summary descriptions of the highway performance classification system.

Case Examples 43 designated as part of the interregional system because of their importance to specific commu- nities or to system connectivity. ND 57 and US 281 from ND 57 to US 2 were both designated as part of the interregional system, despite having volumes below-the-average-interregional- per-mile volumes of approximately 3,500 AADT. ND 57 has outside importance relative to its volume because it provides the only access between Spirit Lake Reservation and City of Devils Lake, where residents can access grocery stores and from which emergency medical services can be provided. US 281 was included in the interregional class because it was determined that the detour that would be necessary if US 281 were not available would impose unreasonable user costs in terms of wasted time, operational costs, and fuel consumption. The decision was made from the perspective of reasonable service level expectations. Recent trends and interest in improvements. North Dakota DDOT is interested in improv- ing their approach to low-volume roads within the fund allocation and prioritization process. In particular, the DOT’s planning staff indicated interest in approaches that could be used to prioritize LVR that serve locations disadvantaged by the level of existing network connectivity, or disadvantaged economically. Currently, these considerations can be accounted for qualita- tively based on local knowledge, but there is also interest within the agency in more quantitative approaches. Another potential improvement cited would be better availability of local freight data, beyond what is available in systems such as the FAF or even some proprietary sources that do not provide estimates of freight movements on LVRs. North Dakota DOT has explored the possibility of using fieldwork and business outreach to collect data on freight movements. However, these data-collection efforts have been hindered by North Dakota’s very strict open record laws, which make companies unwilling to share information on competitiveness grounds. Another trend that may affect prioritization strategies within the DOT, including that of LVRs, is the development of an additional roadway classification scheme for freight. The network is grouped into three freight classes, each with its own performance criteria or targets. The agency is still working to determine how a freight designation will affect a road’s prioritization within the agency investment strategy. Finally, it is worth noting that North Dakota DOT has seen some scrutiny of LVRs when the oil boom in the Western part of the state caused very-low- volume roads to become relatively high-freight-volume facilities that experienced rapid conditions deterioration. This caused classification changes for certain roads within the HPCS. 4.2.4 Nevada: Category 5 Roads in the Maintenance Investment Policy Summary. Nevada DOT defines an LVR as having a volume threshold of 400 AADT and uses this designation for investment policies. The state’s maintenance division maintains LVRs on a set-aside budget. Each of five road classes in the state has its own level of condition distress that triggers repair, as captured by a composite pavement quality indicator. This means that an LVR must be in worse condition for priority repair than a higher classification facility. From Nevada DOT’s perspective, it is important to have funding set asides that are used primarily on LVRs because LVRs cannot compete with higher classes of roads, and this ensures that at least some investment occurs. The maintenance division considers the user profile of LVRs when prioritizing, using an informal checklist and with inputs from district personnel. For example, a school route that provides critical mountain access was moved further up the improvement list. Nevada DOT’s staff is interested in more formally documenting the checklist of strategic considerations that could elevate one LVR above another, and in quantitative measures of social, economic, or environmental considerations.

44 Investment Prioritization Methods for Low-Volume Roads Definition of a low-volume road. In Nevada, the roadway network is divided into five road prioritization categories based on AADT, equivalent single-axle load (ESAL) per day, and high- way classification (Table 15). Each category contains roads that require rehabilitation at similar frequencies as determined through the use of pavement prediction models. Category 5 is defined to include facilities with AADT ≤ 400 and that are referred to as LVRs within the agency. These LVRs comprise approximately 32% of the total system miles (Nevada DOT 2015). Low-volume roads within the investment prioritization process. Given that LVR construc- tion is no longer a part of the DOT’s activities, all investment prioritization policies for LVR are for preservation and maintenance. The department’s Pavement Management System Overview dictates that Category 5 roads be maintained by the maintenance division (2011), using the set-aside maintenance budget. While this budget is not strictly earmarked for LVRs, in practice the majority of these funds are allocated on Category 5, and increasingly also on Category 4, roads. The general process of prioritizing by category had been in place since the mid-1990s and established different levels of distress that trigger more aggressive repair activities according to road class. This means that an LVR must be in a worse condition to receive the same number of points in the conditions rating system (a higher rating is worse) as a higher classification facility. The agency has developed its own pavement ride quality rating system for pavement condition that incorporates multiple aspects of distress (e.g., IRI, friction, or rutting) into one composite indicator (Nevada DOT 2011). The primary concern with LVRs in Nevada is maintaining them to a level of service that is safe for travel. According to maintenance staff, the key point of this approach is that LVRs cannot compete with higher classes of roads and therefore it is important to have a separate set of funds (maintenance funds) that are primarily directed to LVRs—otherwise no investment would occur on LVRs. Consideration of critical strategic issues. The maintenance division within Nevada DOT is responsible for defining the maintenance program, the majority of which is investment in Category 4 and Category 5 roads. Headquarters is assisted by district personnel in this process. As part of program development, staff review and discuss the user profile of each road. Specific uses may push a road further ahead in the prioritization. One recent example is a road that was a school route in the mountains. Because it was the only way for children to get to and from school, this route was moved ahead in the priority list for maintenance funds. District personnel are relied on to relay any specific social concerns or considerations based on their contact with communities. This process implies an informal checklist of broader factors that would raise the priority of an LVR but these factors are not formalized. Recent trends and interest in improvements. Nevada DOT is generally satisfied with its approach to prioritizing LVRs. However, staff did indicate interest in more formal documentation of the checklist of broader social, economic, or environmental criteria to be considered when prioritizing improvements, as well as an update of policy documents to reflect the treatment of Road Prioritization Category Description 1 Controlled access roads 2 ESAL/day > 540 or AADT > 10,000 3 540 ≥ ESAL/day > 405 or 1,600 < AADT ≤ 10,000 + NHS 4 405 ≥ ESAL/day > 270 or 400 < AADT ≤ 1,600 5 AADT ≤ 400 Source: Nevada DOT State Highway Preservation Report (2015). Table 15. Nevada DOT road prioritization categories.

Case Examples 45 Category 4 roads to be similar to Category 5 roads within the maintenance fund allocation pro- cess. There is also interest in the potential for more quantitative measures of social, economic, or environmental considerations. 4.2.5 Idaho: Earmarked Funding for Noncommerce Road Preservation Summary. The Idaho Transportation Department (DOT) divides its network into commerce and noncommerce roads and has a pavement management strategy that focuses available funds on commerce routes. A truck volume threshold of 300 CAADT demarcates these two groups of roads, recognizing the economic importance of freight to the economy and the elevated pavement deterioration rates associated with truck traffic. Idaho has earmarked funds for pavement preservation work on noncommerce routes at a level that provides for stopgap preservation-only treatments. This policy ensures that enough funding is left to make real progress on pavement conditions on other higher priority roads. District offices prioritize within the class of noncommerce roads, based primarily on conditions data, but with flexibility to incorporate other “softer” factors based on the district engineer’s judgment. Their prioritization approach can be described as “data assisted” rather than prescribed or “data driven.” In consultation with the Idaho Transportation Board, Idaho DOT may in the future update the threshold used to define commerce and noncommerce routes, to realign the balance of investment based on trends in system conditions. Definition of a low-volume road. Idaho DOT divides its network into commerce and noncommerce roads for the purposes of defining a pavement management strategy and focus- ing available funding on commerce routes. Noncommerce routes are defined as those with <300 CAADT that comprise 47% of the system (5,726 miles) (Idaho DOT 2016). The grouping by commercial traffic is intended to address both the importance of routes with truck traffic to the Idaho economy and to recognize the more rapid pavement deterioration experienced by roads with higher truck volumes. The Idaho Transportation Board approved this approach in 2015 (Idaho DOT 2016). Low-volume roads within the investment prioritization process. As documented in the FY 2018 Program Update Manual for the Idaho Transportation Investment Program (Idaho DOT 2017), the DOT has decided to earmark funding specifically for pavement preservation work on noncommerce routes. The $18 million per year earmark represents enough funding for preservation-only treatments (seal coats, primarily) to maintain current conditions on noncommerce roads. While these routes may in fact warrant additional work, this stopgap measure has been implemented so as to direct limited pavement funding to higher-priority commerce routes (Idaho DOT 2017). Commerce routes are eligible for “all types of treatments (from sealcoats to full reconstructs), as warranted” (Idaho DOT, page 18, 2016). Idaho DOT established this investment policy to make enough funding available in specific locations to make real progress on pavement condition, rather than spreading money too thinly across the entire network. District offices are responsible for prioritization of pavement preservation work on noncommerce routes through use of a dynamic and flexible decision-making process. These determinations are made primarily based on condition (i.e., worst–first), with the understand- ing that funding levels should be sufficient to seal coat the entire noncommerce network in the next 10 years.

46 Investment Prioritization Methods for Low-Volume Roads Consideration of critical strategic issues. District-level prioritization for noncommerce routes does not formally consider social, economic, or environmental impacts. However, dis- trict offices do have a dynamic decision-making process with some leeway to account for factors beyond roadway conditions. A typical consideration might be the decision not to spend on a seal coat for a section of road if the road will need aggressive treatment in a few years. Other consid- erations can also be accounted for based on the district engineers’ judgment. Recent trends and interest in improvements. The resource allocation strategy for commerce and noncommerce routes is subject to change as funding and network conditions evolve, in con- sultation with the Idaho Transportation Board. For example, the 300 CAADT threshold could be modified later to realign the balance of investment, based on observed trends in conditions between commerce and noncommerce roads. The current threshold was chosen to ensure decent coverage of the state’s primary north–south and east–west routes within the commerce route network. Regarding LVR prioritization in general, Idaho DOT is comfortable with its “data as- sisted” rather than “data driven” process, which uses asset management system data but trusts district office staff to incorporate judgment on softer factors. 4.2.6 South Carolina: Non-Federal Aid Roads and Non-NHS and Load Restricted Bridges Summary. South Carolina DOT has no formal definition of an LVR. However, LVRs are in practice funded through one of three programs: The Non-Federal Aid Secondary Pavement Improvement Program, the Non-NHS Bridge Replacement Program, and the Load Restricted Bridge Replacement Program. South Carolina DOT has formal engineering directives that outline project prioritization processes for each program. Each of the three programs that include LVRs is prioritized in a two-part process, the first of which relies on quantitative scores from pavement and bridge management systems, and the second of which applies “field review criteria” to raise or lower candidate projects based on strategic considerations. Secondary scoring at the district or subdistrict level accounts for harder-to-quantify issues, while still providing a structured framework to investigate the importance of LVRs to connectivity and access (e.g., for emergency services or for freight/ commerce) based on local knowledge. The scores for all criteria are incorporated into an overall project score that represents a multicriteria analysis approach to prioritization. South Carolina DOT staff are satisfied with this approach, as it is both flexible and offers a paper trail from which to respond to inquiries about investment decisions. Definition of a low-volume road. LVRs are primarily funded through one of three programs at South Carolina DOT: The Non-Federal Aid Secondary Pavement Improvement Program (covering approximately 41,393 lane miles), the Non-NHS Bridge Replacement Program (cover- ing approximately 3,880 bridges), and the Load Restricted Bridge Replacement Program (ranging from 300–350 bridges, on average). Low-volume roads within the investment prioritization process. In accordance with legis- lative requirements, South Carolina DOT publishes engineering directives that outline project prioritization processes for each program. Table 16 summarizes the criteria used in prioritization of non-federal aid secondary pavement improvement projects. The process has two parts. The

Case Examples 47 first part is prescriptive and quantitative, based on data included in the pavement management system. In the second part, field engineers add or deduct points from the scores of candidate projects, based on their own local knowledge and judgment, to arrive at a final ranking for approval by the South Carolina DOT’s Commission. Non-NHS and load-restricted bridges are also subject to a two-part process, beginning with quantitative scoring based on output from the bridge management system. The bridge manage- ment system calculates a benefit–cost ratio for each potential bridge replacement, using infor- mation on the structure’s condition, traffic status (closed, load restricted, or recommended for load restriction), total and truck volumes, and detour length. The bridges with the highest benefit–cost ratio receive 1,000 points, and every other structurally deficient bridge evaluated receives a fraction of the points based on the relative ratio between the highest benefit–cost score and the score for that bridge. The DOT runs twice as much money as is available through the bridge management system to generate a list of candidate projects. Districts then receive a list of candidate projects (without their respective scores) and are asked to assign additional scores (listed in Table 17) that add up to a maximum of 500 points, based on the judgment of field engineers. These scores are sent to the state bridge maintenance engineers, who add up the total scores and develop a final ranked list from which projects are selected up to the available budget. Consideration of critical strategic issues. The South Carolina DOT primarily considers social, economic, and environmental impacts related to LVRs through secondary scoring by field engineers at the district or subdistrict levels. For pavement projects, the connectivity criterion gives engineers with local knowledge the latitude to prioritize routes that serve key destinations that are important for social or economic reasons. Similarly, for bridges, district staff are asked to explicitly consider factors such as emergency services access, access to schools, the effects that structurally deficient bridges might have on commerce, and the potential importance of bridges to current and future economic development. The qualitative scoring process offers flexibility to Priority Ranking Score Criteria (0 to 1,000) Field Review Criteria (–100 to 400) Scores assigned by the pavement management system. Routes that pass a certain threshold become eligible project candidates that are sent to field engineers for additional scoring. Scores assigned by field engineers at the county or district level. Points added to a priority ranking score result in a final score used in ranking. Districts asked to score projects for 2–3 times the amount of funds available (to support transparency). Condition (600 maximum) – Pavement Quality Index – International Roughness Index – Percent Patching Volume (200 maximum) – Average Daily Traffic – Average Daily Truck Traffic Role within network (150 maximum) – State Freight Network – Strategic Corridor Network – Functional Classification Coordination with other programs (50 maximum) – State Safety Programs Relative Condition (–100 to 100 points) – Used to lower or raise score based on actual condition (e.g., better/worse than last measured) Corridor Continuity (0 to 100 points) – For segments that would help complete the resurfacing of a corridor through a county or district Connectivity (0 to 100 points) – “For routes that provide connectivity to economic centers, schools, emergency facilities or other key points of public interest.”(page 3) Contractibility (0 to 100 points) – For grouping projects in a given area or within like treatments to reduce costs Source: Assembled from information in South Carolina DOT Engineering Directive 65 (South Corolina DOT 2017a). Table 16. Criteria used in prioritization of non-federal aid secondary pavement improvement projects.

48 Investment Prioritization Methods for Low-Volume Roads account for harder-to-quantify issues, while still providing a structured framework that asks those most familiar with the local context to consider the role of these roads in serving communities. Recent trends and interest in improvements. South Carolina DOT staff view their approach to LVR prioritization as fairly “steady state.” The existing approach offers a helpful mix of prescriptive process and flexible judgment-based evaluation. It ensures there is a paper trail that can be audited or used to respond to queries from public officials. The process also provides a concrete basis for responding to resurfacing requests from the public. 4.3 Case Examples—Key Observations The case examples discussed reveal several insights about how investments on LVRs are pri- oritized, including among different LVRs and between LVRs and other higher volume facilities. For example, • The cases demonstrate a mixture of explicit and implicit consideration of LVRs as a class of facilities within prioritization and programmatic resource allocation processes. Four cases (Missouri, Arizona, Nevada, and Idaho) formally define an LVR by using a volume threshold, Bridge Field Review Criteria Route Continuity and River Basin Upgrades (0 to 125 points) – Ensures that river basins receive additional consideration as these bridges are generally larger, carry more traffic, and also have significant detours if major work or restrictions are required. District Repair Feasibility (0 to 75 points) – Used to evaluate bridge repair history, needs, and effectiveness. Improved Emergency Services and Emergency Evacuation Routes (0 to 75 points) – Ensures that emergency services such as fire and ambulance are considered and that interruptions are minimal; also ensures that hurricane evacuation routes are maintained to a high level, as well as primary and secondary lifeline routes for seismic response. State Freight Network (0 to 50 points) – Added emphasis to roads on the freight network, in accordance with federal guidelines (all or nothing points). Strategic Corridor Network (0 to 50 points) – Added emphasis to roads on the strategic corridor network, in accordance with federal guidelines (all or nothing points). New Schools and/or Changes in Bus Routes (0 to 50 points) – Considers new schools or changing bus routes. Known Commercial Routes (0 to 50 points) – Considers the movement of goods and the impacts that structurally deficient bridges may have on known commercial routes. Future Economic Development (Residential/Commercial) (0 to 25 points) – Criterion used to measure current and future needs and benefits provided to existing or future developments. Source: Assembled from information in South Carolina DOT Engineering Directives 69 and 70 (South Carolina DOT 2017b, 2017c). Table 17. Field review criteria used in prioritization of non-NHS and load restricted bridges.

Case Examples 49 while two other cases (North Dakota and South Carolina) demonstrate how certain classes of roads are effectively inclusive of LVRs despite not being defined strictly in volume terms. Agencies clearly see the value of distinguishing LVRs from other roads (formally or otherwise) to guide planning and investment decision making and recognize the need to treat different classes of roads differently. • In all cases, the investments currently considered for LVRs fall into the realm of maintenance and preservation, rather than investing in new or upgraded facilities. This is indicative of a pervasive environment, in which resources are limited, networks are largely considered “built out,” and investment in new capacity is less common and focused most on areas with high demand. Nevertheless, states see value in maintaining existing LVRs because of their role in providing access and supporting network connectivity. • Traditional engineering metrics—including volumes, conditions ratings, and accident rates— are viewed as necessary but not sufficient to guide LVR project prioritization. States recognize the broader strategic importance of LVRs in serving communities, including by providing access to education, emergency and other health care services, businesses, recreational areas, remote communities, or other key points of public interest. This is particularly true because for many LVRs there are no alternative routes or available alternatives impose significant costs on users because of the length of the required detour. • Because of their local knowledge and close relationship to local governments and the public, district or field engineers play an important role in ensuring that the prioritization process accounts for the broader role of LVRs. This occurs by means of descriptive input, as well as by qualitative scoring (e.g., scoring on a scale from 0 to 100). Quantitative ratings that are specific to LVRs are not prevalent in the reviewed practice. • The separation of lower volume facilities from other classes of roads is used to direct funding away from these roads, while still ensuring there is some basic level of investment in LVRs. These strategies reflect the pressures felt by agencies charged with maintaining assets with insufficient funding, and the balancing act between recognizing that road networks have a hierarchy of importance but that even the lowest class of facilities delivers value to society. • In Arizona, LVRs are scrutinized for jurisdictional turn-back potential, as the state considers the proper definition of its state highway system. Moving forward, LVRs may emerge as one of the frontlines of efforts to “rightsize” transportation system investments. As states grapple with the challenge of matching system size and level investment to societal needs, the ability to distinguish between different facilities with varying degrees of importance is likely to become even more critical.

50 The research in this synthesis documents practices used by transportation agencies to make investment decisions about LVRs. The research responds to interest in methods that address the economic, social, and environmental impacts of LVR investments. Based on a literature review, survey of practice, and case examples, this chapter provides a summary of the primary findings from the research, as well as observations of barriers to widespread implementation of promising methods and identification of remaining knowledge gaps. The chapter is organized into six areas: 1. Motivation for granting low-volume roads special consideration. What are the factors that contribute to a need to treat LVRs differently from other roads within the investment decision- making process? 2. Approaches to defining and differentiating low-volume roads. Which definitions or classification schemes are used to separate LVRs from other roads? 3. Methods for prioritizing low-volume road investments. What methods are used in practice to prioritize projects on LVRs? 4. Evolving issues in low-volume road planning and management. What trends or emerging issues are currently influencing the planning and management of LVRs? 5. Successes and challenges in current practice. Based on the literature review, feedback from the survey, and case example interviews, what insights into successful practice can be gained and what challenges remain with respect to prioritizing LVRs? 6. Knowledge gaps and suggestions for future research. What gaps remain in the body of knowledge on LVR prioritization methods and what types of additional research can help to fill those gaps based on the findings from the synthesis? 5.1 Motivation for Granting Low-Volume Roads Special Consideration • There is general agreement both abroad and within the United States that LVRs offer real value to the economy and to society in ways that cannot be fully inferred from the perspective of traffic volume alone. LVRs facilitate access to trade, to labor markets, and to critical social services and are particularly important for supporting remote communities. They play an important role in facilitating economic development, particularly in economically dis- advantaged regions. LVRs can also support overall resilience by playing a role in emergency preparedness and disaster management. • LVR projects (like roadway projects in general) are pursued to achieve benefits in the areas of travel time and cost savings, economic development, environmental quality, and social ben- efits from improved access to resources such as schools and health care. However, the relative emphasis across these goals is generally different for LVRs, compared with higher-volume roadway investments. There is a greater emphasis on social, economic, and environmental C H A P T E R 5 Conclusions

Conclusions 51 objectives guiding LVR improvements (in contrast to an emphasis on achieving marginal travel time or cost savings for a large user group on higher volume roadways). That difference points to holistic approaches to project evaluation and prioritization for LVRs. • LVRs are generally unable to compete with other classes of higher usage roadways when evaluated with conventional methods in transportation asset management, such as traditional benefit–cost analysis that focuses on user benefits that in turn are based on traffic volume. This lack of ability to compete is the main reason why transportation agencies grant these roads special consideration within prioritization processes through a number of potential approaches. These potential approaches are (a) defining a specific funding program for low- volume roads, (b) applying separate or adjusted criteria to low-volume roads specifically, or (c) incorporating criteria within all prioritization processes that would tend to capture the strategic social and economic objectives of LVRs. • There are well-documented preservation and maintenance backlogs for LVRs. Insufficient upkeep results in long-term costs accruing to agencies (when deferred maintenance results in higher life cycle costs and more costly fixes down the road) and in the imposition of socio- economic costs on communities served by the roads. While funding limitations can be felt across entire transportation networks, the pressure tends to be most acute for LVRs that typically end up lower down on investment priority lists. • The interest in maintaining LVRs depends in part on the specifics of road network size and ownership, which can vary significantly among states. Whereas some states own and manage very large networks that include significant low-volume mileage, other states are responsible for much smaller state systems, leaving proportionally more LVRs under the purview of local (county and municipal) governments. Moreover, the ways in which state and local transpor- tation planning interacts also varies across the country. These specifics inevitably influence the ways in which LVRs are given or may be given special consideration within the resource allocation process. 5.2 Approaches to Defining and Differentiating Low-Volume Roads • Based on survey results, there is a nearly even split between agencies that do and do not adopt specific definitions of LVRs in North America. Of those agencies that do define LVRs, both volume-based and other criteria are used, and there is no single volume threshold common to all. • However, even among those agencies that do not report a specific classification of LVRs, there are still agencies that have another category of road that maps largely to the lower volume part of their network. For example, South Carolina reported that three of its funding programs— Non-Federal Aid Roads, Non-NHS Bridges, and Load Restricted Bridges—tended to de facto include mostly LVRs. In practice, these other categories also influence investment prioritization for LVRs. • Network and funding program definition are important structuring determinants of an agency’s overall investment prioritization strategy, including for LVRs. DOTs are subdividing their networks in increasingly intentional ways to enable better performance-based planning, including conditions and performance tracking, and to support ongoing conversations about the appropriate allocation of resources across elements of a transportation system. 5.3 Methods for Prioritizing Low-Volume Road Investments • Prioritizing LVR investments typically begins with a core set of engineering data and analysis, often organized within pavement and bridge management systems that weigh agency life cycle costs against user travel time, safety, and vehicle operating costs. There have been continual

52 Investment Prioritization Methods for Low-Volume Roads improvements over time in the state of asset management systems and their use in state DOT planning and investment decision support. Nevertheless, data availability for LVRs still presents a challenge, even for basic inputs such as volumes and roadway conditions. These data are expensive to collect and therefore agencies do not always have the resources to collect or update such information as routinely as is the case for higher volume roads. • Most transportation agencies supplement more traditional engineering analyses with addi- tional evaluation processes to address the economic, social, and environmental conditions or impacts of LVR investment decisions. These approaches vary in their complexity and include a mix of quantitative ratings, qualitative scoring (e.g., 0 to 10), and descriptive approaches. For example, decision makers may use measures of economic distress to target investments at particularly dependent or needy areas and may use a checklist of criteria to determine if an LVR provides critical access for industry, to education or health care, or for emergency services. Many approaches used by state DOTs rely in some form on local knowledge and judgment that has been provided by district engineers or other local transportation planners. 5.4 Evolving Issues in Low-Volume Road Planning and Management • Transportation funding constraints in North America have led, paradoxically, to both more and less attention paid to LVRs in agency funding decisions. While less funding can result in resources being directed away from LVRs, less funding can also lead to closer scrutiny of these roads as agencies try to figure out how to manage needs vis-à-vis limited resources. • In a resource-constrained environment, it will become increasingly important to under- stand the value of ensuring minimum tolerable or basic access to remote communities and to understand the roles that LVRs play in this provision. • Federal requirements related to asset management planning and performance management are indirectly shaping the planning and management of LVRs. For example, in Missouri, the development of an asset management plan to meet federal requirements led to a more complete understanding of networkwide asset condition and needs, and ultimately to a new policy on how LVRs can be prioritized and funded. In addition, more than one state reported in the survey that NHS designation and associated federal performance management requirements have affected the level of emphasis on LVR. • Jurisdictional transfer and consideration of appropriate state network size are issues raised by more than one state in the case example interviews. Given funding constraints, state DOTs facing large preservation burdens are increasingly likely to confront questions about the appro- priate size and scope of state highway networks, which in turn can lead to closer scrutiny of LVRs. Arizona recently completed a planning study of LVRs, with the objective of identifying candidates for jurisdictional/agency route transfer or cost saving measures. It is possible that these roads will become a key subject of emerging efforts to “rightsize” transportation systems. • The emphasis on incorporating broader strategic effects of LVR projects into prioritization methods is also part of a wider conversation within transportation planning about how to capture the strategic purposes of transportation improvements within resource allocation decision making. These conversations will likely remain interconnected and offer the potential for mutual learning. 5.5 Successes and Challenges in Current Practice • As shown in the case examples and survey responses, state DOTs have had success identifying broader strategic issues to address within their LVR prioritization processes.

Conclusions 53 • There is also agreement among interviewed state practitioners on the value of having flexible approaches that can incorporate bottom-up input and local knowledge that may not be available through centralized data-driven processes alone. • Nevertheless, there are still barriers cited by survey respondents related to the sufficiency of methods for capturing the importance of LVRs, sufficient availability of data and agency resources, and external stakeholder or internal agency buy-in. 5.6 Knowledge Gaps and Suggestions for Future Research The following knowledge gaps were identified in the course of this synthesis and could be addressed with further research, as discussed below: • Structured approaches to incorporating broader strategic objectives of low-volume road investments into decision making. While many states have had success in identifying broader strategic objectives to be addressed in LVR prioritization, there is still a need for additional practice-oriented research on best practices in this area. Research might address the following: (a) development of checklists of key strategic considerations for transportation agencies to consider that might elevate one LVR improvement above another, (b) further development of quantitative metrics and methods that address already identified factors of importance, (c) approaches to identify and target areas with accessibility or economic disadvantages, and (d) methods for addressing the concept of vulnerability, dependence, or criticality of infrastruc- ture in investment decision making. Such research would enable DOTs to pursue approaches that are systematic but also flexible, sensitive to local knowledge, and appropriately matched to the level of available data and agency resources for LVR evaluation. • Jurisdictional transfer evaluation to support the goal of rightsizing highway networks. Responding to the issue of jurisdictional transfer and appropriate state network scope, there is a need for further guidance on how to identify and evaluate opportunities for transferring ownership and responsibility between states, counties, and localities. This topic is currently being addressed in the ongoing NCHRP Project 19-14, “Right-Sizing Transportation Investments— Methods for Planning and Programming.” • Interjurisdictional partnering and coordination in funding and prioritization of local low-volume road improvements. Whereas this synthesis has focused on the topic of LVR prioritization from the perspective of state DOTs, a large proportion of the investment decisions affecting LVRs are made by local or county governments. Those decisions are in turn influenced by sources of funding and by guidelines or requirements set at the state or federal level. Practitioners would therefore benefit from additional research on successful interjurisdictional partnering and coordination for funding and management of locally owned LVRs. The research need includes understanding opportunities for better decision making through a range of partnership arrangements between states and localities, from facilitation and technical assistance, to incentivizing desired management and investment approaches, to the applications of specific requirements to the use of state funds at a local level. • Optimizing tiered level of service targets as a function of agency and societal costs. Agencies are increasingly dividing their networks into tiers to facilitate performance target setting, investment prioritization, and tracking of achieved level of service over time. However, the basis for setting targets and level of service expectations is an area with additional research needs. LVRs in particular are subject to increasing scrutiny about appropriate levels of invest- ment and levels of service. States would benefit from guidance on how to set standards that respond to funding constraints and reflect expected changes in the accrual of agency, user, and wider societal costs and benefits.