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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Suggested Citation:"Appendix I: Case Studies." National Academies of Sciences, Engineering, and Medicine. 2019. Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future. Washington, DC: The National Academies Press. doi: 10.17226/25334.
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Appendix I Case Studies INTRODUCTION Twenty-two case studies were analyzed to support the committee’s delib- erations regarding needs and strategy orientation. Not necessarily repre- sentative of all Interstate needs, the case studies are illustrative examples to support reasonable judgements regarding needs analysis. This synthesis reviews four key observation areas for the 22 project- or plan-based case studies: 1. Drivers and Deficiencies 2. Improvement Approaches 3. Forecasted Future Performance 4. Project Costs CASE STUDY OVERVIEW The case studies were identified using selection criteria that entailed geo- graphical factors, user types, and improvement strategies (see Table I-1). Following the descriptions of groupings used to categorize the case studies, Table I-2 presents a brief description of the case study projects and plans as well as the rationale for their selection. 511

512 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM TABLE I-1 Selection Criteria for Case Studies Geography Users Improvement Strategies • Urban/Metro • Interurban • Rural • Commercial/Freight • Passenger • Preservation • Operations • Capacity • Technology TABLE I-2 Brief Description of Case Study Projects, Plans Projects/Plans Description and Rationale CA, Bay Area Express Lanes The Bay Area is planning a 550-mile network of Express Lanes by 2035 to improve the operational efficiency. Metropolitan Transportation Commission (MTC) will operate 270 miles of the 550-mile Express Lanes network through conversion of 150 miles of existing carpool lanes to Express Lanes and addition of 120 miles of new lanes. This case study investigates highway improvements being undertaken in this area, and captures metrics relating to forecasted improvements in operational efficiency. CA, I-8 CRCP, Imperial County This case study involves 48 miles of pavement reconstruction with continuously reinforced concrete pavement. The pavement sections are designed to last up to 70 years with appropriate application of pavement preservation techniques. CA, I-15 Integrated Corridor Management, San Diego The 20-mile segment of I-15 between SR 78 and SR 52 is one of two demonstration sites for Integrated Corridor Management in the United States. This important inland commuting corridor between northern San Diego and Escondido and portion of the freight corridor between the Mexican border and Las Vegas incorporates the integration of numerous ITS systems, transit, and reversible express lanes to optimize the capacity and reliability during peak period use, incidents, and special events. A multi-agency collaborative effort to manage all available assets in a coordinated and integrated fashion has been shown to reduce person hours traveled and improve travel time reliability. CA, I-710 Gerald Desmond Bridge, Long Beach The Gerald Desmond Bridge carries I-710 serving as a major access point to the Port of Long Beach from downtown Long Beach, California, and surrounding communities. The traffic LOS on the bridge is forecast to operate at LOS F in year 2030, while the existing bridge was physically deteriorated. The $1.5 billion replacement project will build six-lane, cable-stayed design bridge, with a 205-foot clearance to allow the newest generation of cargo ships to enter the Port. The bridge will include emergency lanes on the inner and outer shoulders, as well as a bicycle/pedestrian path. The case study focuses on the bridge replacement project as well as the long-life concepts used for bridge design. The bridge will be designed for 100 years using the emerging service life design concepts with a special emphasis on material durability in a harsh marine environment.

APPENDIX I 513 Projects/Plans Description and Rationale CO, SMART 25 Managed Motorways, Denver This $7 million Managed Motorways demonstration project will add sensors to the lanes on the northbound side of 13 miles of I-25 south of downtown Denver. This stretch has 17 points of access or egress, including the interchange with E-470. Typically, the northbound lanes operate at around 60 mph until 7:15 AM, but then break down to 30 mph as traffic volumes grow during the morning rush hour. Working in collaboration with VicRoads (the transportation department in Victoria, Australia, where Melbourne is located) Colorado Department of Transportation (CDOT) is installing a network of sensors in the corridor that will send traffic data (number of cars in a lane and travel speeds) to VicRoads, which will analyze the information in real time and send directions back to upgraded ramp meters in this section of the highway, telling them how many cars to allow on to the highway. This system will smooth traffic flow, filling gaps, and avoiding pockets of saturation. It is estimated to deliver the additional capacity equivalent to a new travel lane. The SMART 25 demonstration is expected to go live in the spring of 2018. If it functions as expected, CDOT is likely to expand the system. Other states including Utah, Georgia, and North Carolina are following the pilot closely and may follow suit as well. FL, Southeast Florida Express Lanes Network: 595 Express This comprehensive express lanes network includes several vital express lane systems currently in operation, construction, or planning/design in Miami-Dade, Broward, and Palm Beach Counties. The systems are part of Florida’s Strategic Intermodal System, a designated network of transportation facilities important to the state’s economy and mobility that receives priority consideration for funding. Population growth, economic competitiveness, and climate resilience are driving these improvements. GA, I-85 Kia Boulevard Interchange, West Point, Troup County This case study focuses on the construction of a new diamond shaped interchange in Troup County in west central Georgia. This interchange will provide safe and efficient access an adjacent Kia automobile manufacturing plant and training facility. The new facility was expected to generate thousands of daily automobile and truck trips to and from the site vicinity enroute I-85. The interchange was opened to traffic in 2008. IA, I-80/I-29, Divided Dual Freeway, Council Bluffs The case study is a typical Interstate modernization project in a mid-sized urban area to address future transportation needs. The project involves major widening and interchange improvements to construct a dual, divided freeway with three express lanes to through I-80 traffic and two local lanes to I-80/I-29 traffic. TABLE I-2 Continued continued

514 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM Projects/Plans Description and Rationale KY-IN, I-65 Ohio River Bridges, Louisville The primary intent of this project is to address inadequate cross-river system linkage opportunities and relating congestion impacts on the Kennedy bridge and interchange, given that no viable alternatives are available for at least 50 miles on either sides along the Ohio River. This project improves cross-river mobility through the construction of a new bridge, interchange reconfiguration, and freeway rerouting through a by-pass roadway. MN, I-535 Blatnik Bridge, Duluth This case study focuses on the application of life-cycle performance modeling and cost analysis in developing an optimized life-cycle plan for future bridge maintenance, rehabilitation, and replacement decisions. The case study documents existing bridge conditions, future performance risks, evaluation of remaining life, development of feasible alternatives of preservation strategies, and recommendation of an optimized life-cycle activity plan and associated investments necessary to maintain the bridge for the next 15 to 40 years. NV, Future I-11-Phase 1 and Phase 2, Boulder City This project addresses the concerns of lack of contiguous interstate connectivity for interurban passenger and freight travel between Phoenix and Las Vegas. Upon completion, this project will provide connectivity between I-15 through I-515 spur and Arizona State Line. This route is one of the congressionally designated high-priority corridor (#26) for its importance to the nation’s economy, defense, and mobility. NY, I-590 Winton Interchange, Rochester This case study involves an interchange reconfiguration project in Rochester, New York. This $5.6 million project, which was completed in 2013, upgraded a traditional diamond interchange to a diverging diamond interchange. Prior to reconfiguration, the interchange experienced high crash rates and significant delays during peak hours. OH, I-75 Reconstruction, Allen County I-75 is one of the nation’s most heavily traveled truck freight corridors. Deteriorating bridge and pavement conditions, narrow shoulders, and other design deficiencies were identified on this section of I-75 near Lima in Allen County, Ohio. These deficiencies lead to increased maintenance costs, increased risk of crashes, and increased delay during crashes. This three- project reconstruction corrected design deficiencies, reconfigured interchanges, increased the overhead clearance of overpasses, and constructed an auxiliary lane between two interchanges. TABLE I-2 Continued

APPENDIX I 515 Projects/Plans Description and Rationale PA, I-70 New Stanton Interchange Two substandard interchanges on the I-70 corridor in New Stanton, Pennsylvania, were consolidated into a single modern interchange with a double roundabout configuration. This interchange, which is located about 1 mile away from the I-76/I-70 system interchange, was constructed in response to higher crash rates, poor LOS at ramps, and outdated design standards. The $53.7 million project included a new, relocated interchange with double roundabouts at ramps, a park-and-ride facility, pedestrian access, and replacement of a structurally deficient bridge deck. The concept of roundabouts was preferred to improve safety and operational performance. RI, Iway I-195 Relocation, Providence The reconstruction of I-195 through Providence was an opportunity to correct numerous design deficiencies and replace deteriorated bridges combined with the reclamation of 20 acres of downtown, riverfront property for redevelopment. The project reconstructed and relocated a 1.6-mile segment of I-195 and an adjacent 0.8-mile section of I-95. The project included 14 new bridges with a 1,200- foot, 8-lane mainline bridge over the Providence River, 25 lane-miles of new Interstate, a new interchange with I-95, 5 miles of new city streets, and 4,100 feet of new pedestrian riverwalks. The redesigned highway segments provide improved operational characteristics and safety. The freed-up parcels are being redeveloped as an “innovation and design” district. TX, I-35A Waco Project 5A Increased truck traffic along the I-35 corridor coupled with regional population growth in Texas created travel demand that exceeded capacity. The existing I-35 facility through Central Texas is an essential element of the local and regional transportation system. The purpose of the project was to meet local and regional travel demands by increasing capacity and upgrading the transportation infrastructure to meet current FHWA and Texas DOT design standards for interstates, bridges, and frontage roads, thereby improving the safety of travelers along I-35. The project included widening 13.4 miles of I-35 from 4 to 6 lanes, upgrading on- and off-ramps, converting frontage roads to one-way, and converting underpasses to overpasses. TX, I-69 Upgrade of US 77 This proposed project is upgrading the existing 8-mile four-lane divided facility to Interstate standards. The existing facility has many at-grade unsignalized intersections to provide access to local roads and ranch gates. The proposed project is reconstructing the existing roadway with grade-separated intersections and frontage roads to maintain access to local traffic, 70-mile free flow speed, and ensure highway safety. This route is a part of a congressionally designated High-Priority Corridor (#18) to provide new connections for freight travel between Rio Grande Valley and Michigan/Canadian border, facilitate freight oriented multimodal integration with rail, air, and inland water transportation at Memphis, and improve interstate connectivity of many towns in western Tennessee. TABLE I-2 Continued continued

516 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM Projects/Plans Description and Rationale TX, US 75 Integrated Corridor Management, Dallas The 28-mile stretch of US 75 (which effectively operates as an interstate) between Plano and downtown Dallas was selected as one of two Integrated Corridor Management demonstration sites in the United States. The corridor includes a minimum of 8 GP lanes, concurrent flow HOV lanes, frontage roads, parallel arterials, and a parallel light rail line served by park-and-ride lots. Multiagency coordination and a decision support system with pre-programed response plans is the heart of a system that alerts drivers to cascading alternative routes and modes in the event of an incident on US 75. Travelers can be directed to the frontage roads, a parallel arterial, or transit depending on the location and severity of the incident. Demonstration results indicate a reduction in person hours traveled and improved travel time reliability. UT, I-15 Corridor The 400-mile section of I-15 through Utah is a critical corridor from two distinct perspectives. In one sense, I-15 represents a critical north-south corridor through a predominantly rural state with significant implications for rural community access and mobility, interstate and intrastate freight movement, and access to recreation and energy production sites important to the state’s economy. The corridor also passes through the geographically constrained Wasatch Front that encompasses the Salt Lake City- Provo-Orem metropolitan region, home to more than 80 percent of the state’s population, where I-15 serves as a major interurban corridor. Therefore, planning for future improvements includes both traditional rural interstate widening and interchange projects as well as innovative mobility improvements along its urban stretch where further widening is limited. VA, I-66 Outside the Beltway, Fairfax The I-66 project, which was procured recently using public– private partnership service delivery model, intends to address the existing problems, primarily relating to inadequate capacity, localized choke points, and unreliable travel times, on this 22- mile corridor, as well as to meet the future person-through-put demands using diverse travel mode choices. This project will add 22 miles of managed lanes to relieve congestion, improve safety, enhance travel model choices using bus and rail transit integration, park-and-ride lots, reconstructing roadways and interchanges. This commuter-heavy corridor exemplifies an integrated multimodal approach to mobility to address growing capacity needs in metropolitan areas. TABLE I-2 Continued

APPENDIX I 517 Projects/Plans Description and Rationale WA, I-405 Corridor, Seattle Originally intended as a bypass route, the 30-mile corridor of I-405 in east suburban Seattle is Washington State’s second most heavily traveled expressway. High growth in population, employment, and traffic congestion characterize the largely suburban region that surrounds the corridor. The corridor exemplifies the multi-pronged approach to mobility, with multimodal enhancements, necessary to address corridor capacity deficiencies in urban regions. Widening for Managed Lanes, HOV lane conversion, a direct connector to existing express lanes, interchange enhancements, peak-period shoulder use, and improved routing and frequency of enhanced bus and BRT service are all incorporated into a multi-project, phased corridor plan supported with sizable non-federal revenue generation. WY, I-80 Connected Vehicle Pilot I-80 across southern Wyoming is a significant Interstate freight corridor (and intrastate route) with 30–55 percent of traffic being trucks, rising to 70 percent seasonally. The corridor experiences challenging weather conditions impacting safety and the economy through road closures and incidents. Gaps exist in the ability to detect road and weather conditions and to communicate traveler information and influence driver decisions. To help address these deficiencies, Wyoming DOT is engaged with U.S. DOT to implement a CV pilot along the corridor that will (1) improve road condition reporting by gathering data from equipped snow plows and trucks, (2) add in-vehicle dissemination of advisories to support speed management, detours, parking, and presence of maintenance and emergency vehicles, (3) provide current and forecasted road conditions to fleet managers, and (4) develop local V2V communication of road condition and posted speeds. To accomplish this, the pilot will deploy and evaluate several CV technologies: 75 roadside units to broadcast messages via DSRC, 400 onboard units (fleet vehicles, commercial trucks) to collect and transmit data, V2V and V2I applications to enable communication with drivers for alerts and advisories regarding various road conditions, and improvements in WYDOT’s traffic management and traveler information practices by using data collected from connected vehicles. TABLE I-2 Continued

518 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM The case studies were grouped into four “case study categories” based on the geographical, user characteristics, and improvement strategies. • Urban Corridors/Regions: This category of case studies explores the needs of Interstates in some of the top metropolitan areas of the nation. Primarily catering to commuter traffic, the freeways in these densely populated urban areas serve as arterials to many residential clusters and employment centers that sprawl along the corridor. While most segments of the freeways are fast approaching capacity levels resulting in increased congestion, safety risks, and travel time reliability issues, roadway expansion strategies, such as new connections and lane additions, are not often viewed as sus- tainable and effective, as a steady growth in travel demand contin- ues to outpace any added roadway capacity. Furthermore, capacity expansion in these areas is often constrained by local geographical factors and high right-of-way costs. The highway agencies gener- ally opt for a combination of operational strategies, such as the use of managed lanes, with or without limited capacity expansion, to manage demand and create additional efficiencies in traffic flow. The case study projects and plans included in this category are primarily the application or demonstration of advanced traffic management strategies, combined in some cases with reconstruc- tion or capacity expansion: i. I-66 Outside the Beltway in Northern Virginia ii. I-405 Corridor Express Lanes in Washington State iii. Network of express lanes in Southeast Florida iv. Express lane planning in the San Francisco Bay Area v. I-15 Corridor through the Wasatch Front metropolitan region in Utah vi. Integrated Corridor Management along I-15 in San Diego vii. Integrated Corridor Management along US 75 in Dallas viii. Managed Motorway demonstration along I-25 in Denver ix. Relocation of I-195 in Providence, Rhode Island • Interurban/Freight Corridors Traversing Urban Centers: The case study projects include multi-state corridors in mid-sized cities. When Interstate corridors carrying freight and interurban traffic traverse through urban centers, congestion chokepoints may fre- quently occur due to localized surge in traffic demand from local traffic. These problems are often exasperated by physical bottle- necks (e.g., bridges for cross-river mobility) and convergence of

APPENDIX I 519 multiple high-volume roadways (e.g., more than one Interstate or U.S. route). Highway agencies may find feasible opportunities for capacity addition to manage congestion. The case study projects identified for this category include (i) I-65 Ohio River Bridges in Louisville, Kentucky, (ii) I-80/I-29 Dual Divided Freeway in Council Bluffs, Iowa, (iii) Future I-11 Boulder City Bypass in Clark County, Nevada, and (iv) I-35A Waco Project 5A in Waco, Texas. The first two case studies investigate the levels of service of freeway segments and interchanges of Interstates that pass through the cities of Louisville and Council Bluffs, which were originally constructed in the 1960s, while the third case study investigates the option of a new “bypass” connection that is being built with an intention of avoiding a freeway cutting through the commercial strip of Boulder City, and the last case study examines the more straightforward approach of adding capacity and upgrad- ing infrastructure to meet current standards. • Interchanges: This category can apply to all three identified geog- raphies and comprises a system interchange (freeway-to-freeway, or all free-flow movements from one roadway to the other, and vice versa) or a service interchange (one or more movements must stop via stop sign or signal or yield to movements on the other roadway). Interchange improvements are considered operational in nature and often serve to improve mobility, safety, and accessibil- ity. Three case studies investigate service interchanges: (i) diverging diamond interchange upgrade at I-590 and Winton Road outside Rochester, New York, (ii) new interchange along I-85 providing access to a new Kia Motors Manufacturing plant in Troup County, Georgia, and (iii) double roundabout interchange upgrade along I-70 in New Stanton, Pennsylvania. Several system interchanges of varying complexity are included as components of other case studies. • Rural Corridors: This category includes rural segments of Interstate roadways. Four case studies were included: (i) the rural component of the I-15 corridor in Utah, (ii) the upgrade of US 77 in Texas to Interstate design standards for future I-69E, (iii) the reconstruction of I-75 near Lima in Allen County, Ohio, and (iv) the demon- stration of connected vehicle (CV) infrastructure and applications along I-80 in Wyoming. The rural component of the I-15 corridor intends to capture traditional deficiencies in rural segments, common capacity and operational improvement types that are being undertaken, and associated costs. The US 77 case study looks at the adequacy of geometric design elements involved in the upgrade of existing

520 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM roadways to Interstate design standards in rural areas. I-75 is one of the nation’s most heavily traveled truck freight corridors and required reconstruction to correct design deficiencies and reduce the maintenance burden. Wyoming’s I-80 experiences safety and economic impacts from largely weather-related incidents along this critical freight corridor. It seeks to decrease the occurrence and severity of these impacts through connected vehicle technologies deployed on a demonstration basis. • Roadway Assets: This category can apply to all three identified geographies and includes projects that primarily involve preserva- tion (i.e., rehabilitation, partial or total reconstruction) of roadway assets, particularly pavements and bridges, within the existing foot- print. These projects may utilize future technologies, such as long- lasting materials and accelerated construction techniques, long-life design concepts, and asset resilience considerations. The case study projects included in this category are (i) the reconstruction of I-8 pavements in Imperial County, California, using Continuously Reinforced Concrete Pavement, (ii) the replacement of the I-710 Gerald Desmond Bridge in Long Beach, California, and (iii) an optimized life-cycle plan for future bridge maintenance, rehabilita- tion, and replacement decisions applied to the I-535 Blatnik Bridge in Duluth, Minnesota. CASE STUDY GOALS The specific goals of the case studies are to gain valuable insights relating to the following aspects of modeling: • What improvement types are being planned or implemented at project level to meet future needs? Why were they undertaken? What are the drivers that influence those deficiencies? What aspects of condition or performance did they address? What is the fore- casted growth in vehicle-miles traveled (VMT) at the project level based on the drivers considered? • What is the general philosophy in identifying Interstate improve- ments relating to capital highway improvements versus non-highway improvements? How are various improvement types bundled? • What additional strategies are highway agencies incorporating to address safety, land use, quality of life, and environmental con- siderations? How are these strategies influencing the performance related to these considerations? • How well are the improvement types addressing the needs of pas- senger users, commercial users, and non-users (community) in

APPENDIX I 521 either qualitative or quantitative terms? The performance metrics that are being evaluated include, but not limited to, metrics relating to travel demand, travel mode, mobility, and safety. • Update unit costs for traditional construction (e.g., capital improvements). • What is the actual, expected, or projected improvement in performance/service life with the adoption of modern technology, construction techniques, materials, and features? • What is the forecasted growth in travel demand at regional or corridor level, and what is the expected performance under an ap- proved plan? (for plans only) • Were strategies used as a surrogate to direct Interstate improve- ments because of local goals (e.g., densification, alternate modes, and demand management)? What is the effect of these surrogate improvements on future Interstate? (for plans only) • Are highway disinvestment or decommissioning strategies being planned or implemented on Interstate roadways? If yes, what are the consequences on system performance, such as percentage change in pavement condition, bridge condition, weight restrictions, speed, control access, vehicle miles of travel, and vehicle hours of travel? DRIVERS AND DEFICIENCIES Demographic Growth Demographic growth is the most common driver behind the decision to invest in the 22 Interstate study highway case study improvement projects. Population growth is explicitly stated as a key driver for 16 of the 22 case studies, including all five of the urban commuter traffic projects, both inte- grated corridor management projects, and the SMART 25 demonstration in Denver. An additional three projects—the I-590 Winton Interchange near Rochester, New York, I-75 Reconstruction in Ohio, and the I-35 widening in Waco, Texas—cite modest population growth or the need to provide capacity for future traffic as a driver to invest in Interstate improvement projects. The project documentation also cites long-term population growth rates over 25- to 40-year periods as an additional demographic driver for the case study projects, with expansion rates ranging between 22 and 72 percent. Growth in employment is cited as a driver for 11 of the case study projects. Growth in the number of households is also cited as a driver be- hind the I-66, Ohio River Bridges, and Future I-11 case studies. Several of the case study projects have additional region-specific drivers that complement population and employment growth in densifying urban and metropolitan areas. For example, the lack of affordable housing and

522 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM the need to meet greenhouse gas–reduction targets are both cited as drivers behind the San Francisco Bay Area Express Lanes network. The documen- tation for the I-15 Integrated Corridor Management project in San Diego also cites housing growth as a driver, especially in less expensive locations in southeast Riverside County, which increases commuter volumes in the corridor. While it may be implicit as a driver in other locations, enhanc- ing local quality of life is also cited as need for the 595 Express project in Broward County, Florida. In addition to growth in employment and population, the related growth in VMT and daily traffic delay are cited as drivers for the US 75 Integrated Corridor Management project in the Dallas-Fort Worth Metroplex. Accessibility and Mobility The need to improve accessibility and mobility is cited as an important driver behind nine of the case study improvement projects. The specific ac- cessibility needs vary among the case study projects. For example, with the 595 Express project, two accessibility related drivers are cited: the need to eliminate congestion on the sole east/west Interstate corridor in Broward County and the need to support goods movement to and from Port Ever- glades and Fort Lauderdale Hollywood International Airport. The corridor is also designated as part of the Florida DOT’s Strategic Intermodal System (SIS), which has significant funding available for capital improvements. Supporting goods movement and trucking is also an important driver for the I-15 corridor in Utah, where statewide truck freight is expected to grow 55 percent by weight between 2012 and 2040 and 111 percent by value. The I-35 widening from Waco to West in Texas is driven by the need to ac- commodate international and intracity truck traffic, which accounts for 29 percent of AADT. These projects address bottlenecks on important freight corridors as they intersect urban centers. High truck volumes (30–55 per- cent, and up to 70 percent seasonally) are also cited as a need for the I-80 Connected Vehicle Pilot in Wyoming. One of the primary needs for the I-710 Gerald Desmond Bride project in Long Beach, California, is providing adequate roadway capacity to ac- commodate traffic moving to and from and between the port of Long Beach and the Port of Los Angeles. An additional accessibility driver is the need to raise the vertical clearance of the bridge to provide adequate clearance for larger post-Panamax cargo vessels using the port. This is important to the future competitiveness of the largest port in the United States. In Denver, one of the drivers behind the SMART 25 demonstration project is the desire to restore the mobility benefits of the $1.6 billion T-REX project, which was completed in 2006 and added highway and rail capacity in the corridor. Improving accessibility and mobility are also drivers on projects in more rural settings, including the Future I-11 in Nevada, the upgrade of US

APPENDIX I 523 77 south of Corpus Christi, Texas, and the I-85 Kia Boulevard Interchange in Georgia. The Future I-11 project will expand existing rural capacity, while the US 77 will replace a four-lane highway in kind with a four-lane Interstate facility. Both of these projects are on high-priority international freight corridors providing Interstate connections between Canada and Mexico. These projects will also provide new Interstate highway connec- tions between important domestic locations, Las Vegas and Phoenix in the case of Future I-11, and Houston and Brownsville, Texas, with the US 77 upgrade. The US 77 project is also intended to improve system continuity on an existing rural highway with speed limits that vary between 30 and 70 miles per hour. The I-85 Kia Boulevard Interchange will provide enhanced access to a Kia Motors manufacturing plant and by so-doing improve eco- nomic development opportunities and employment growth. The Ohio River Bridges project addresses the deficiency of adequate cross-river capacity between southern Indiana and Louisville, Kentucky. It enhances cross-river mobility by adding a second bridge in the I-65 corri- dor and with the construction of a new crossing and greenfield connecting highways to the east. The need for expanded hurricane evacuation routes is cited as an additional accessibility driver for projects providing access to coastal communities, including the 595 Express and US 77. Safety and Operational Improvements Improving safety conditions is a common driver among a majority of the case study projects. In certain cases, safety is cited directly as a project driver. In others, specific factors that contribute to deteriorating safety are cited as deficiencies that need to be remediated. For example, the I-66 project is intended to address several deficiencies influencing safety, such as travel demand exceeding capacity, severely congested conditions during peak hours, deficient geometric features, and unreliable travel conditions. Similarly, the I-405 Express Toll Lanes address inadequate capacity, de- lays and congestion, and weaving friction at interchanges. The 595 Ex- press project addresses similar issues including speed differentials between through traffic and vehicles exiting the highway, weaving frictions, and a lack of auxiliary lanes near interchanges. The Ohio River Bridges address interchanges and bridge congestion on I-65, which is also an important trucking corridor. Although safety issues are not mentioned directly with the I-80/I-29 Dual Divided Freeway project in Council Bluffs, Iowa, its primary drivers are safety-related. This project will improve the capacity and configura- tion of two heavily traveled interchanges in order to separate local and through traffic, as well as traffic on I-80 and I-29. The project will address several related issues, including geometric deficiencies, weaving friction, and poor volume-to-capacity ratios. This is a common theme among projects

524 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM involving the replacement or upgrade of older Interstate facilities that do not comply with current design standards. This includes the reconstruction of I-75 in rural Allen County, Ohio, the I-195 Iway project in Providence, Rhode Island, the I-70 New Stanton Interchange in Pennsylvania, and the widening and reconstruction of I-35 from Waco to West in Texas. Safety is a primary driver of both case study projects involving the upgrade of local highways to full Interstate system standards. The future I-11 project in Boulder City, Nevada, will address severe congestion on US 93, which operates at level of service (LOS) F during peak periods with speeds between 30 and 40 miles per hour and a high volume-to-capacity ratio. This project also features a 15.5-mile bypass route around Boulder City that will eliminate un-signalized intersections, as well as direct access from the highway to local businesses and homes. Safety is cited as the primary driver of the upgrade of US 77 to future I-69 between Kingsville and Driscoll, Texas. While the existing highway is not congested, the upgrade project will remove at-grade intersections with US 77, reduce high crash rates on the highway, and safely accommodate the high preponderance of truck traffic and future growth in trucking. Structural Integrity The structural integrity of older projects is one of the key deficiencies trig- gering the need for replacement and rehabilitation projects, particularly for bridges. The need for a structurally sound and seismically resistant bridge is the primary driver of the I-710 Gerald Desmond Bridge replacement. In Duluth, the need to improve the structural adequacy was also the primary driver for the I-535 Blatnik Bridge project. Similarly, the reconstruction of I-75 in Ohio was driven by the need to reconstruct pavements and bridges in the corridor. Managed Lane Drivers and Deficiencies The case studies include two projects intended to remediate deficiencies relating to managed lanes. The I-66 project will address the issue of a lack of travel alternatives to single occupancy vehicle (SOV) trips in the corri- dor. This managed lane project will encourage ride sharing, as well as the provision of improved transit options. The I-405 Express Toll Lane project addresses the fact that the HOV lanes it replaced did not meet federal speed targets, raising the possibility that federal maintenance funds could have been revoked by the Federal Highway Administration (FHWA). FHWA considers HOV facilities to be degraded if they fail to maintain a minimum average operating speed of 45 miles per hour 90 percent of the time over a consecutive 180-day period during morning or evening weekday peak hour periods (or both for a reversible facility).

APPENDIX I 525 Other Drivers and Deficiencies Constraints to highway widening is cited as a deficiency with the I-15 proj- ect in Utah, as are the impacts of highway widenings with the Bay Area Express Lane Network. As a result, to the maximum extent possible, the Bay Area express lane network will be created by converting existing HOV facilities to high occupancy toll (HOT) operation. Existing highways will only be widened where gaps exist between current HOV facilities. However, due to the impacts of highway widenings, not all gaps will be filled. The I-80/I-29 Dual Divided Freeway project will address the poor condition of the current highways, which is cited as a deficiency, while the I-8 pavement reconstruction project in Imperial County, California, is driven by the fact that the pavement is nearing the end of its useful life on this interurban and freight corridor. In Utah, the I-15 project is intended to improve a number of current and projected deficiencies, including reli- able person throughput, access, air quality, economic outcomes, household transportation costs, and modal balance in the corridor. In Rhode Island the desire to implement the City of Providence Old Harbor Plan was an important driver behind the reconstruction and relo- cation of I-195. This opened 35 acres of waterfront property to develop- ment, thereby reuniting Downtown Providence with the Jewelry District, improving waterfront access and transportation, expanding parkland, and providing economic development opportunities. Other drivers for the I-80 Connected Vehicle Pilot include challenging weather conditions such as wind and snow. A key driver for the 13.4-mile I-35 widening project from Waco to West is that it is part of a larger high- profile program to widen 96 miles of I-35. IMPROVEMENT APPROACHES Key observations on improvement approaches can be made by the implied geographies and physical contexts of the case study categories. Urban Corridors/Regions Operations More Than Capacity Large urban regions are often characterized by mature Interstate (and other freeway) networks, with constrained geographies, little unused right-of-way, and expensive construction environments limiting the ability to implement capacity expansion solutions. Capacity-related deficiencies are increasingly being addressed with operational solutions centered around demand man- agement strategies (see Table I-3). New capacity is not impossible, but a balanced approach must be struck, as demonstrated with express toll lane

526 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM (ETL) additions that include HOV/general purpose (GP) lane conversions and new tolled capacity (I-66 Outside the Beltway, I-405 ETL, Bay Area Express Lanes). These selected projects indicate a rough cost for HOV-to- ETL conversion of $3 million per mile and range for new ETL construction of $7.5 million to more than $40 million per mile (see Table I-11). The lower end of new ETL construction corresponds to fewer urban, undeveloped regions, while the upper end includes ancillary asset reconstruction (two bridges). Costs also vary depending on the need for right-of-way acquisition and the by the number of ramps and interchanges included. Advanced corridor solutions are also emerging that seek to holistically manage a complete corridor from a multimodal perspective (integrated cor- ridor management) and that tightly control an interstate corridor’s capacity TABLE I-3 Predominant Improvement Strategies in Urban Corridor/ Region Case Studies Selected Urban Corridor/Region Case Studies Operational Improvement Approaches I-66 Outside the Beltway Managed lanes—HOV 3+ and buses travel free Conversion of 1 GP lane to 1 ML Conversion of existing HOV 2+ to HOV 3+ New and improved bus routes New transit stations and 3 park-and-ride facilities with 4,000 parking spaces (to promote transit and ride-sharing) Access points to transit stations and park-and-ride facilities Geometric and safety improvements, including auxiliary lanes between interchanges I-405 Express Toll Lanes Demand management using managed lanes (pricing—ETL) Transit shoulders Peak-use shoulder (subsequent improvement) Multimodal enhancements—BRT line and stations, expanded local bus service, increased vanpools, park-and-ride spaces (planned for future) San Francisco Bay Area Express Lanes Express lanes—HOV conversion, GP lane conversion, lane additions I-15 Integrated Corridor Management Integrated Corridor Management—integrates managed lanes (express toll lanes), ramp meters, ITS, incident response improvement, traffic signal coordination, multimodal enhancements (bus rapid transit, improved traveler information) US 75 Integrated Corridor Management Integrated Corridor Management—integrates a managed lane (HOV), ITS, incident response improvement, traffic signal coordination, multimodal enhancements (light rail transit/parking, improved traveler information) SMART 25 Managed Motorways Managed motorways—advanced system of ramp meters and traffic sensor technology to reduce congestion by optimizing access and density of traffic

APPENDIX I 527 in real time through sophisticated algorithms (managed motorways). These solutions will be necessary to maximize person throughput and the effi- ciency of a constrained physical corridor. In some, likely infrequent cases, the opportunity to recapture valuable urban footprint—socially and economically—may present itself during ur- ban Interstate reconstruction activities, which as with operational solutions, may be combined with modest capacity enhancements. One case study examines this scenario, as summarized in Table I-4. As discussed in the previous section, strong growth in population and employment is a prime driver for improvements in urban regions. Modest or even substantial capacity-oriented corridor or network improvements, often at great cost, may not be sufficient as growth continues and capacity or efficiency gains are soon overtaken. Two example regions that have now turned to applying advanced operational strategies to address continued congestion growth illustrate this observation: • I-25 underwent significant widening under the $1.67 billion “T- REX” project between 2001 and 2006. However, a 40 percent increase in traffic volumes between 2006 and 2015 eroded the project benefits. Colorado DOT has turned to a managed motor- ways demonstration to recapture those benefits, and seeks to gain the equivalent of a new lane through this advanced operational strategy at a fraction of the cost. • US 75 north of Dallas was fully reconstructed between 1992 and 1999, in one section as a depressed freeway with cantilevered frontage roads due to right-of-way constraints. The $600 mil- lion project expanded the freeway from four to six lanes to eight. TABLE I-4 Redevelopment in an Urban Corridor/Region Case Study Selected Urban Corridor/Region Case Studies Improvement Approaches Iway I-195 Relocation Preservation: Pavement/bridge reconstruction—I-195 alignment shifted 2,000 feet to the south opening over 35 acres of prime waterfront property to redevelopment in Downtown Providence (5 miles of new city streets, 4,100 feet of new pedestrian river walks, and the restoration and improvement of India Point Park) Capacity: Interchange reconstruction—reconfiguration of all highway ramps between I-195 and I-95, eliminating sharp curves and short weaves; reconfiguration of ramps between the two highways and Downtown Providence Some widening from 3–4 lanes plus auxiliary lanes to 4 lanes plus auxiliary lanes

528 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM Light rail transit also opened along the corridor in 1998 and a concurrent flow HOV lane in 2007. Continued population and employment growth—the Dallas region has been adding roughly 1 million people every 7 to 8 years—has driven a need for further improvement, but without any possibility of further corridor ex- pansion, integrated corridor management incorporating the exist- ing freeway, light rail, and parallel arterials became an operational solution worth investigating. Evolving Urban Characteristics Large urban regions also exhibit evolving corridor or network charac- teristics that have influenced the selection of improvement approaches. Aside from absolute growth in population and travel destinations—most especially employment—mature urban regions’ clustering of origins and destinations can change (organically or by design/policy) and its overall geographic extent tends to grow over time. For example: • I-66 in Northern Virginia stretches across a corridor extending west from the Washington, DC, metro area, with higher growth and more vacant land at the west end, and lower growth and in- creasing density and land redevelopment at the east end, thereby driving a need for greater capacity along the full corridor as the metropolitan region grows. • Similarly, employment growth and rising housing costs/cost of living in San Diego County have led to significant population and housing growth in southwestern Riverside County to the north. Commuter traffic along I-15, the principal inland north–south route between northern San Diego and Riverside Counties and downtown San Diego has seen resultant growth in congestion, delay, and reduced travel time reliability. • The I-405 corridor east of Seattle was originally constructed in the mid-1960s as a bypass, but it now serves as an intra-suburban and suburban-urban commuting corridor connecting several suburban cities with significant employment destinations, as well as providing connection to several east–west routes that access downtown Seattle. • The San Francisco Bay Area today is characterized by polycen- tric employment destinations (and living origins) with major tech companies from downtown San Francisco to the South Bay/Silicon Valley, manufacturing sites for various industries in the East Bay (e.g., Hayward and Oakland), and the state’s largest cluster of life science and biotech companies, as well as educational institutions and national labs throughout the region—all driving a need for regional mobility solutions.

APPENDIX I 529 Network Planning and Regional Collaboration Urban improvement approaches at the regional scale suggest several ob- servations about network planning and regional collaboration. Here it is often difficult or impractical to isolate deficiencies and improvements at the Interstate corridor level. It is necessary to evaluate them across non- Interstate elements as well, including arterials, and to consider the impacts and effects of parallel or complementary transit service. For example, the San Francisco Bay Area Express Lane Network include Interstate, state route, and U.S. route segments. Parallel arterial capacity and transit ser- vice were weighed in the evaluation of scenarios along the I-15 corridor through the Salt Lake City Metropolitan Region. Multimodal options and the use of parallel routes (often arterials) are essential elements of integrated corridor management, for which a focus on optimizing the throughput of a constrained urban Interstate corridor must broaden out to all corridor options in the face of limited capacity expansion opportunities. Finally, improvement approach feasibility and selection may depend to a greater degree on the number of agencies involved and their institutional context. • In the Bay Area, the metropolitan planning organization (MTC) has lead planning for express lanes and the development of the long-range plan that programs all projects, but actual implementa- tion responsibility is divided among MTC and two county-level agencies, and furthermore, design and construction is the respon- sibility of the state DOT, Caltrans. • Express lane planning in Southeast Florida has been led by Florida DOT, with collaboration from the state toll agency, metropolitan planning organizations, and regional toll authorities. • The Wasatch Front Central Corridor Study examining a host of improvement approaches was co-led by two metropolitan plan- ning organizations, with collaboration from the state DOT and the regional transit agency. • Strong institutional partnerships among regional entities are neces- sary to enable successful integrated corridor management systems. San Diego’s MPO, the San Diego Association of Governments, is the lead agency for the I-15 Integrated Corridor Management (ICM) that also relies on collaboration and coordination among the state DOT, state police, two transit agencies, three cities, local first responders, law enforcement, and county emergency services. All participants have agreed on “posture responsiveness” that char- acterize the nature of actions plans and operation of subsystems that comprise the ICM system based on corridor demand and im- pact of the event. A certain level of individual agencies’ operational control is forgone while trust is placed in the collective response of

530 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM all partners based on the ICM system’s decision support system’s recommendation. Incremental Approaches Generally urban improvements with a capacity element are expensive and technically or politically challenging. An incremental approach may be necessary depending on individual corridor or corridor segment feasibility and financial capacity. • Along the I-405 corridor near Seattle, dual express toll lanes were necessary from an operational performance perspective, but ini- tially only financially feasible for 10 of the corridor’s 17 miles. In the long term, a second ETL will be added, but in the short term other incremental solutions have been applied, including additional GP lane capacity via auxiliary lanes where possible and selected transit use shoulders. Post-project completion, Washington State DOT added a peak-use shoulder lane where most needed, paid for with toll revenues collected on the express toll lanes. • The San Francisco Bay Area Express Lane Network has been re- fined over time through several planning cycles and has now moved into full-fledged implementation that balances what is most feasible with what is most needed in the near-term. Evolving corridor de- mand patterns continue to drive refinements to what segments are included and in what sequence they will be implemented. • The Southeast Florida Express Lane Network is undergoing ag- gressive implementation with significant, dedicated state funding. In fact, regional express lane planning is occurring statewide. Cor- ridors in Southeast Florida typically involve reconstruction and widening, as opposed to projects found in other regions that exclu- sively or partially incorporate simpler lane conversions with com- paratively little new capacity. The state made a policy decision in 2013 to toll all new capacity in the state, meaning new Interstate/ freeway capacity will necessarily be express toll lanes. • The Iway project in Providence has extended across many years, with the environmental analysis under way throughout the 1990s and construction from the early 2000s, with the hallmark Iway Bridge opening to service in 2007 and all new roads, bridges, and ramps in use at the end of 2010. Related work restoring local streets and completing new development projects in the 35 acres of land opened by the relocation of the highway is ongoing as of 2017. Work to realize this vision for the redevelopment of down- town Providence has extended over 30 years.

APPENDIX I 531 Roadway Reconstruction Costs The roadway reconstruction costs in small urbanized (population be- tween 50,000 and 200,000) and large urbanized (population greater than 200,000) areas cannot be estimated effectively for two reasons: first, bid tabs were unavailable because the case study projects in urbanized areas were procured using design-build and public–private partnerships, and second, because the case study projects in urbanized areas in other areas included significant work on bridges, ramps, and interchanges, the roadway reconstruction costs could not be effectively segregated from other items. Interurban/Freight Corridors Traversing Urban Centers Capacity-focused improvement approaches are predominantly found out- side the largest urban regions. Significant Interstate projects in this regard exist along key interurban and freight corridors, often where Interstate through-traffic mixes with local, urban (often commuter) traffic exposing safety deficiencies and creating bottlenecks. As summarized in Table I-5, these deficiencies have been addressed with: • New capacity either along existing right-of-way (likely incorpo- rated into full corridor reconstruction) or new/re-alignment − Widening: express and local lanes on I-80/I-29 (Council Bluffs, Iowa), new lanes along I-35 (Waco, Texas) − New connections/linkages: Ohio River Bridges’ new I-65 Bridge and East End Crossing − Realignment: US 93/US 95 (part of Future I-11) − New alignment/bypass: Future I-11 (Boulder City, Nevada) • Interchange addition, reconstruction, or reconfiguration • New bridges or bridge widening and/or reconstruction Rural Corridors Rural corridors typically do not face the same kinds of constrained right-of- way challenges found in urban regions, except where challenging or sensi- tive geographical features may be found. Rural corridors tend to require improvement approaches in the form of (see Table I-6): • Traditional widening projects to accommodate rural mobility and accessibility needs and intrastate/interstate truck freight volume growth. • Functional upgrades or correction of design deficiencies to ac- commodate volume growth and/or improve safety through access control and grade separation.

532 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM TABLE I-5 Predominant Improvement Strategies in Interurban and Freight Corridor Case Studies Selected Interurban/Freight Corridor Case Studies Capacity Improvement Approaches I-65 Ohio River Bridges Downtown Crossing: Building a new I-65 bridge with six NB lanes (Segment 2) Reconfiguration of Kennedy Interchange (I-64, I-65 and I-71) (Segment 1) East End Crossing: New East End Bridge 2,500 feet (Segment 5) 3.5-mile extension of KY 841 from I-265 to East End Bridge (Segment 4) Reconfiguration of Partial Interchange at US 42 (Segment 4) 1,700-foot tunnel under US 42 and the historic Drumanard Estate (Segment 4) 4.5-mile new roadway from East End Bridge to Lee Hamilton Highway (Segment 6) New interchange at Old Salem Road (Segment 6) Reconstruction of the SR 265/SR 62 interchange (Segment 6) I-80/I-29 Dual Divided Freeway Capacity addition from 6 lanes to 14 lanes Reconstruction of two interchanges Other improvements include (i) new bridge over UPRR, (ii) rebuilding of Nebraska Ave and Madison Ave Interchanges, (iii) new I-29 SB lanes and bridges for US 275/Iowa 92, four Interstate ramps, and (iv) railroad consolidation Future I-11 Boulder City Bypass Phase 1: US 93/95 Interchange New diamond interchange with connector ramps and 1.5 mile- frontage road Realignment of US 93/US 95 to develop an access controlled 2.5-mile from Foothill Drive to Silverline Road, with 1,200-foot-long retaining wall and 5 miles of tortoise fencing 360-foot long steel truss bridge under United Pacific Railroad Phase 2: BC Bypass New 12.5-mile, limited access, 4 lane divided highway facility at a design speed of 70 mph as bypass to US 93 (Future I-11) New interchange at US 95 intersection (with 3 bridges) Reconfiguration of existing Nevada interchange at SR-172 8 bridges = 3 over intersecting streets, 3 over deep canyons, 1 over drainage way, and 1 for wildlife crossing Scenic view parking area I-35A Waco Project 5A Access upgrade Conversion of frontage roads to one-way operations General-purpose lane additions—widening from 2 to 3 lanes

APPENDIX I 533 Among the case study projects in rural areas (population less than 5,000), the average cost of reconstructing a lane is estimated at $1.3 mil- lion per mile, while adding a lane is estimated at $2.8 million per mile. For small urban areas (population between 5,000 and 50,000), the average cost of lane reconstruction or addition is approximately $2.8 million per mile. See Table I-11 for additional detail. The application of technology to address operational and safety con- cerns in rural corridors is likely to be a growing improvement approach along rural corridors, especially those critical to interstate and intrastate freight movement. The connected vehicle pilot along I-80 in Wyoming is the best example of this. Interchanges Several case studies examine the reconstruction or addition of new inter- changes as a capacity improvement to address mobility, safety, and ac- cessibility issues interchange projects of both types—service and system interchanges—form a significant portion of the Interstate construction ac- tivities in all geographic areas. These projects involve reconstruction and reconfiguration of existing interchanges as well as new interchanges along the corridor to address capacity, access, and operational needs. TABLE I-6 Predominant Improvement Strategies in Rural Corridor Case Studies Selected Rural Corridor Case Studies Improvement Approaches I-69 Upgrade of US 77 to Interstate Standards Preservation: Highway and interchange reconstruction, pavement reconstruction Operations: Geometric improvements Capacity: Interchange improvements and additions I-15 Rural Corridor—Utah Capacity: Lane additions (including bridge widening), interchange upgrades, new interchange I-75 Reconstruction Preservation: Road reconstruction of 9.38 miles (no capacity addition but with provisions for future expansion), pavement reconstruction, bridge replacement Operations: Realignment of intersecting roads, flattening of curves, noise walls Capacity: Reconstruction of five interchanges I-80 Connected Vehicle Pilot Operations: ITS Technology: Connected vehicle applications to improve situational awareness, communications, and traveler information dissemination • Roadside units, mobile weather sensors I2V • Onboard units (trucks and snowplows) V2V, V2I

534 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM The interchange reconstruction and reconfiguration projects were pre- dominantly driven by capacity, operational and structural needs in response to substandard or outdated design standards, higher V/C, poor level of ser- vice, higher crash rates, and structural deficiencies. Depending on the needs, these projects may entail a wide range of activities, such as reconfiguration and localized improvements, widening, structure replacement, realignment or relocation, and major improvements to intersecting roads. The most common service interchanges (i.e., one or more movements must stop at a stop sign or signal or yield at yield sign to movements on the other intersection roadway) that are in use today are diamond and partial cloverleaf interchanges. Inherent to these interchange types are operational and safety problems associated with left turns and conflict points. In addi- tion, when the need for capacity expansion arises, both these interchange designs require a larger footprint, and thus, causing cost and right-of-way challenges in urban areas. The reconstruction of service interchanges in- volving structure only replacement or installation range between $2 million and $6 million; if major improvements such as widening are included, the cost range can be between $25 and $50 million. Construction of new ser- vice interchanges indicate roughly range from $30 million to $55 million. Table I-11 provides additional cost information. When these interchanges reach structural and/or operational perfor- mance thresholds, many agencies are increasingly exploring alternative designs in urban areas, including diverging diamond interchanges (DDI), single-point urban interchanges, and double roundabouts. These alternative interchanges are reported to provide significant reduction in crash rates. On the I-590 Winton Road Interchange Reconstruction project, the selection of DDI resulted in significant cost savings for the right-of-way purchase and projected to result in shorter traffic times, fewer and less severe crashes due to elimination of many conflict points, and fast construction. To date, more than 25 states have installed DDIs. Similarly, double or triple drop roundabouts are gaining prominence in states, such as Colorado and Penn- sylvania. The reconfiguration of existing service interchanges with DDI exhibits a cost range of $3 to $8 million (see Table I-11). The reconfigura- tion of existing service interchanges with roundabouts or single-point urban interchanges ranges from $11 to $18 million. The reconfiguration and reconstruction of system interchanges (i.e., freeway to freeway, or all free-flow movements from one roadway to the other, and vice versa) in urban areas, such as the Kennedy Interchange in downtown Louisville where I-65, I-71, and I-64 intersect and the I-80/I-29 East and West System in Council Bluffs, Iowa, are driven by similar set of capacity, operational, and structural needs. However, the system inter- changes are more complex in configuration with multiple legs, vertical roadway levels within the interchange, structures and loops, and thus, in- volve multi-year, multi-phase, expensive projects with costs typically more

APPENDIX I 535 than $100 million. (Four selected system interchanges from three case study projects ranged between $72 and $600 million.) However, as discussed in following sections, the interchange improvements in urban areas are projected to mitigate performance issues in the near term; however, these benefits may not be sustainable in the longer horizon with increasing future traffic demand. New system and service interchanges are being built to (i) create new or realigned access, (ii) upgrade grade-separated intersections to interchanges along the corridor to reduce congestion and streamline traffic flow, and (iii) convert at-grade intersections to interchanges when non-Interstate highways are upgraded to Interstate standards. Roadway Assets Roadway assets are project elements that can be found in all three case study categories discussed above, aside from interchanges. Major elements addressed in several case studies include pavements and bridges. Pavements The improvement approaches associated with pavements are preservation methods and life-cycle design and cost considerations. Technology may also be applied in the form of long-life structural designs. The case studies focused only on the pavement reconstruction projects of existing roadways: I-8 pavement reconstruction in Imperial County, California, and I-75 roadway reconstruction in Allen County, Ohio. In both case studies, the life-cycle-based end-of-useful life considerations, as influenced by historical pavement condition and remaining service lives, primarily influenced the decision to reconstruct. The engineering deci- sions for reconstruction were optimized to produce pavement designs with minimum practicable life-cycle costs over a longer horizon by adopting the recent advances in materials, and engineering design methodologies such as the innovative long-life design concepts. While it is a common practice to optimize pavement designs and subsequent rehabilitation cycles for a 30- to 50-year period, the I-8 reconstruction adopted a design that required no major rehabilitation activity for at least 55 years. Pavement reconstruction also provided opportunities to mitigate or eliminate underlying causes of premature pavement failures. For instance, the existing pavement section within the Ohio I-75 roadway reconstruction project historically exhibited poor performance due to drainage issues in subbase and foundation. The pavement was repaired, rehabilitated, and resurfaced with bituminous overlays five times between 1973 and 2004. Each rehabilitation event produced a service life of 8 years in compari- son with the expected life of 12 years for this group of pavements. Total

536 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM reconstruction was required to address recurring issues deep within the pavement structure. Among projects in rural and small urban areas that involved widening or reconstruction, the cost of pavement installation was approximately $1.3 million per mile. The case studies did not provide a corresponding estimate for small or large urbanized regions. Bridges Preservation and capacity improvement approaches to bridges are incorpo- rating longer service life designs, especially using greater material durability, and optimized life-cycle plans governing future bridge maintenance, reha- bilitation, and replacement decisions. The case studies primarily focused on bridges with complex structures, such as cable-stayed bridges, that involve long spans, high vertical clear- ances, and typically located over water. Four complex bridge structures analyzed under three case studies ranged in unit cost from $480 to $630 per square foot (see Table I-11). This cost range was also influenced by the application of 100-year service life designs. By comparison, the 2016 Na- tional Bridge Inventory estimated the national average bridge cost on the NHS as $213 per square foot, ranging from $62 per square foot in Texas to $674 per square foot in Hawaii. Most of the bridges on the Interstate System, which were originally built in late 1950s and 1960s, were designed for a design life for 50 to 75 years with HS-201 loading assumptions. Recent projects, particularly com- plex bridges, are adopting 100-year “service life” based designs using newer design standards (e.g., updated seismic design criteria) and heavier loading configurations (e.g., HS-25 and HL-93). The case study bridge projects— I-710 Gerald Desmond Bridge in Port Long Beach, I-65 Abraham Lincoln Bridge in Louisville, and I-265 East End Crossing Bridge, the latter two part of the Ohio River Bridges project, as well as the technical evaluation of the I-535 Blatnik Bridge over Saint Louis River in Duluth, Minnesota—adopted 100-year service life based designs. Life-cycle engineering considerations are increasingly considered in the selection of the type and timing of bridge rehabilitation and replacement strategies. In response to the structurally deteriorating I-535 Blatnik Bridge, the Minnesota DOT (MnDOT) commissioned a technical study to investi- gate various bridge rehabilitation and replacement strategies for restoration 1 The HS-20, which was the design standard in the early 1950s, consists of a hypothetical vehicle, i.e., tractor truck with semi-trailer, with 8,000 lbs. on the front single axle and 32,000 lbs. on each of the two tandem axles. The HS-20 is considered the minimum design load recommended for bridges on Interstates.

APPENDIX I 537 of structural and functional adequacy of the bridge. The technical study, which involved detailed structural, life-cycle cost and risk analysis of 12 different scenarios, has provided a template for MnDOT to make optimal life-cycle based decisions. Looking Beyond the Next 20 to 30 Years The sections above outlined key observations for three broad case study categories based on projects being implemented in response to the contexts of today—the drivers, deficiencies, applications of technology, and regional geographic, demographic, and regulatory/institutional environments. It may be possible to forecast what types of improvement approaches may be nec- essary as each of the three case study category regions continue to evolve, in some cases from one to another. Rural Corridors Rural corridors may tend to remain rural well into the future, and con- tinue to require incremental capacity upgrades as today. Corridor demand growth and travel patterns also may cause some rural corridors to begin to exhibit the deficiencies of today’s interurban/freight corridors, requiring in the future the more complex capacity upgrades applied in those contexts. Connectivity may begin to significantly address certain operational and safety concerns associated with incidents (weather, crashes, work zones, etc.). The affordability of long-term maintenance in low-volume rural re- gions or rural regions with a high percentage of Interstate volume may be a growing concern. Interurban/Freight Corridors Interurban corridors of today may start to exhibit the challenges of con- strained urban environments in the future. Even now, the level of service improvements from, for example, capacity improvements of the Ohio River Bridges project are only marginal, and congestion is forecasted to return in the long term. Operational and demand management strategies, especially pricing as applied today in large urban regions, may become required in these contexts. Urban Corridors/Regions Large urban regions may continue to deploy priced managed lane facilities and networks, but urban physical constraints will only get more challeng- ing. In some cases, it may become necessary to consider full corridor pricing

538 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM to physically (trip diversion to alternative routes or modes) or temporally (shift in trip time of day) optimize the usage of all capacity. Other demand management and integrated corridor/multimodal strategies, often incorpo- rating a pricing element, will also be deployed to optimize corridor perfor- mance from a person throughput perspective. Two approaches poised to move from demonstration status to the mainstream are integrated corridor management and managed motorways. A number of urban regions are preparing planning studies and concepts of operation for ICM including Fort Lauderdale, Kansas City, New York City, Philadelphia, Phoenix, and others. Caltrans opened a relatively less complex ICM system than the one in San Diego along the stretch of I-80 between the Carquinez Bridge and the Bay Bridge in Contra Costa and Alameda Counties. It is more likely that future ICM systems will be imple- mented incrementally rather than as one full, multimodal and multi-strategy system, as with the San Diego and Dallas pilots. Post-demonstration, SANDAG continues to operate and maintain its ICM system. It has further lowered the threshold to activate the system dur- ing an incident, increasing reliance on the decision support system and part- ners to manage system components. SANDAG is also considering applying segment-based thresholds to account for the variability in traffic and inci- dent impact conditions along the full corridor. Continued growth in traffic along the corridor will only continue to make the system indispensable. The managed motorways concept has the potential to increase the throughput of congested urban-suburban Interstate corridors without add- ing new lane capacity by optimizing access and therefore the distribution of vehicles along the Interstate corridor itself. Colorado’s experiment with the managed motorway technology will have important repercussions around the United States. State DOTs in Utah, Georgia, and North Carolina are following the pilot with great interest and if the results are positive they are likely to advance managed motorway tests of their own. The Wasatch Front Central Corridor Study in Utah has addressed some of these future scenarios for I-15, choosing to recommend the improvement approaches summarized in Table I-7 (those listed relate specifically to the Interstate; the study made additional recommendations pertaining to arteri- als, transit, active transportation, etc.). In all cases, the effects of rapidly evolving technology, especially con- nected and automated vehicles must be taken into account. Additionally, several major metropolitan regions have stated that the next iterations of their long-range plans will include greater consideration of technology applications, especially CV/AV, in the evaluation and selection of improve- ment projects.

APPENDIX I 539 FORECASTED FUTURE PERFORMANCE Travel Demand The case studies gathered information on both travel demand and available metrics related to mobility, travel mode share, and safety. Travel demand, in terms of average daily traffic or VMT, is expected to grow annually by geography (see Table I-8). As observed in the case studies, travel demand in urban corridors/regions is expected to grow by 0.5 percent to 2 percent. Lower growth is generally observed in the denser urban environment, such as the easterly segments of I-66 in Fairfax County and San Francisco Bay Area, where future land use patterns trend toward repurposing for higher land use intensity, whereas, higher growth is observed in suburban segments of the corridor, such as the westerly segments of I-66 in Prince William County, where vacant lands are being developed to cater to more afford- able housing needs. Travel demand along interurban/freight corridors is generally forecast to grow by 2 to 3 percent. These forecasts are apparently based on pro- jected increases in population and employment in mid-size cities as well as increases in freight traffic due to economic growth. Rural regions tend to see forecast growth rates of 1 to 2.5 percent, although the case study sample size is small and varied. Freight traffic is also a significant contributor to this expected growth in rural regions. Many of the case studies categorized as interurban/freight corridors, rural corridors, and roadway assets carry significant proportions of trucks and are identified within transcontinental freight networks. TABLE I-7 Improvement Strategies for I-15 Corridor I-15 Urban Corridor—Utah Improvement Approaches Operations Choice Architecture TDM Strategies (application of behavioral economics to incentivize travel choices that benefit system as a whole) Comprehensive TDM Strategy (TDM elements used by existing Traffic Management Associations in the region) Fully-priced Freeways with Barrier-separated “Reliability” Lanes Capacity Expanded Collector-Distributor System (Separate but parallel roadways that connect to freeways reducing congestion from freeway entrances and exits) [Assumed as baseline by 2050] Managed Motorways, Express Lane Widenings, all highway/transit expansions in 2015 long-range plan Technology Pay-Per-Use Transportation App (“Mobility as a Service”) (Subscription-based package of transportation services, e.g., bike share, car share, Uber/Lyft, transit trips)

540 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM Mobility Urban Corridors/Regions Mobility metrics reported for urban corridors focused predominantly on peak hour throughput and travel time. These metrics were generally de- rived using microsimulation models such as CORSIM and VISSIM. In comparison with the no-build option, the introduction of managed lanes has an apparent positive effect on the mobility performance of GP lanes. For example, as observed in I-66 and I-15 corridor studies, the travel times on GP lanes are expected to decrease by 45 percent and 4 to 30 percent, respectively, in the future (i.e., 2030–2040), while the I-405 and Bay Area express lanes show about 40 percent and 15 percent improvement in travel speeds, respectively. TABLE I-8 Estimates of Annual Growth in Travel Demand Case Study Case Study Category Travel Demand Growth Estimates VA I-66 Urban Corridors/Regions Westerly Segments = 1.0 to 2.5% Easterly Segments = 0.5 to 1.0% WA I-405 Urban Corridors/Regions 1 to 2% CA Bay Area Urban Corridors/Regions 1% UT I-15 Urban Corridors/Regions 1.2 to 1.7% RI I-195/I-95 (Iway) Urban Corridors/Regions 0.7%a KY-IN I-65 ORB Interurban/Freight Corridors 1.90% NV Future I-11 Interurban/Freight Corridors 2.70% IA I-80/I-29 Interurban/Freight Corridors 3.10% TX I-35A Interurban/Freight Corridors 1.7 to 2.0% TX US 77 Upgrade Rural Corridor 2.61% OH I-75 Rural Corridor 1.4%b CA I-8 Roadway Assets—Pavement (Rural Region) 1.2 to 2.3% NY I-590 Interchange (Urban Region) 0.7 to 0.8%c aPeak period estimates from 1990 to 2015. bForecasted growth between 2002 and 2032. Actual growth between 2002 and 2016 was –0.7 percent. cForecasted growth between 2005 and 2028. Actual growth between 2002 and 2014–2017 was significantly greater than forecast along I-590 but well below forecast for the Winton Road ramps. NYSDOT could not offer an explanation for this disparity.

APPENDIX I 541 The managed lanes are expected to carry a significant share of the vehicle throughput, particularly during the peak hour periods. The peak hour vehicle throughput indicate a share of 70:30 on general purpose and express lanes on the South East Florida Express Lane Network, 67:33 on I-66 and 45:40 on the I-15 corridor. Among the case studies presented, only actual operating data for the I-405 Express Lanes is available (see Table I-9). The forecasted mobility metrics (volumes and speeds) of I-405 Express Lanes compare well to actual usage during the first 15 months of operation. However, note that the forecast and actual peak periods are not identical; the actual peak periods are longer than originally forecasted. The combination of managed and GP lanes collectively results in im- provements to vehicle and person throughput as well. When compared with the GP lane only option, both managed and GP lanes are projected to increase vehicle throughput by 33 percent on the I-66 corridor and 73 percent on the I-405 corridor. Person throughput is estimated to improve by 43 percent on the I-66 corridor. The managed lanes are expected to shift away a portion of GP lane person throughput, for example about 8 percent on the I-66 corridor, apparently through toll-free incentives for high occupancy vehicles and bus transit options. Emerging advanced operational strategies applied to urban corridors— integrated corridor management and managed motorways—are also in- tended to improve mobility focusing on delay reduction/travel time savings and travel time reliability. The three demonstration projects illustrating these techniques are new enough not to have robust performance results re- ported, but nonetheless analysis, modeling, and simulation techniques have produced performance estimates for the two ICM pilots, and the managed motorways demonstration is aiming to achieve mobility improvements in line with what has been observed in Melbourne Australia’s M1 Motorway on which the demonstration is based. These three pilots’ mobility metrics are summarized in Table I-10. TABLE I-9 Comparison of Forecasted and Actual Mobility Metrics of I-405 Express Lanes I-405 Express Lanes Dual ETL Section GP ETL Total % ETL Forecast (6–9 AM) 15,700 (43 mph) 8,000 (60 mph) 23,700 34% Actual (5–9 AM) 17,200 (44 mph) 8,600 (59 mph) 25,800 33% Forecast (3:30–6:30 PM) 13,700 (32 mph) 8,090 (60 mph) 21,790 37% Actual (3–7 PM) 19,300 (30 mph) 9,900 (56 mph) 29,200 34%

542 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM TABLE I-10 Mobility Improvement Metrics—ICM and Managed Motorways Demonstrations Mobility: Person-Hours Traveled/Year Improved Versus Worsened Travel Times (Differential) Reliability: Buffer Time(s) Variability: Avg. Travel Time(s) I-15 ICM San Diego SB AM—without ICM 14,302,100 — 142.5 636.7 SB AM—with ICM 14,192,500 — 138.8 632.2 Improvement 0.8% +4.0% 2.6% 0.7% NB PM—without ICM 19,248,800 — 132.5 635.0 NB PM—with ICM 19,090,200 — 126.6 629.0 Improvement 0.8% +2.7% 4.5% 0.9% Annual Delay Reduction 268,200 Improvement 3.3%a US 75 ICM Dallas SB AM—without ICM 19,782,900 — SB AM—with ICM 19,775,600 — Improvement 0.04% +1.0% NB PM—without ICM 15,503,000 — NB PM—with ICM 15,492,800 — Improvement 0.07% +1.4% Annual Delay Reduction 17,500 Improvement 0.14%b Average Traffic Flow (vphpl) Average Travel Speeds Travel Time Reliability SMART 25 Managed Motorways Denver—Benchmark Performance from Melbourne Australia M1 Motorway, VicRoads AM Peak 4.7% 34.9% 148.7% PM Peak 8.4% 58.7% 516.4% aBased on 35 hours of annual freeway delay per person and AADT of 230,000. bBased on 49 hours of annual freeway delay per person and AADT of 250,000.

APPENDIX I 543 Interurban/Freight Corridors Mobility metrics reported for interurban/freight corridors included volume/ capacity ratio, travel time and speed, and intersection level of service. For these case studies, the proposed capacity expansion strategies are expected to bring immediate improvements in freeway and interchange LOS. Al- though the magnitude of performance improvements vary from project to project, the model forecasts generally indicate a terminal design year LOS of C, D, or E for all case study projects. For instance, the Ohio River Bridges project increased the number of lanes from 3 to 8 to facilitate the mobility of north–south I-65 traffic across the Ohio River. The congestion LOS estimates for the I-65 bridges show marginal improvement from F for no-build to C or D for the as-built alter- native. Similarly, on the Future I-11 project, the construction of the Boulder City Bypass, a tolled facility, would divert about 20 percent of traffic on US 93; yet, the LOS of interchanges along US 93 is expected to show marginal improvement from E to D in the future. Terminal LOS estimates of C, D, or E lend themselves to questions about the performance expectations of the facility beyond the future design year, which is only about 15 to 25 years into the future. In other words, future LOS expectations raise questions about the sustainability of capacity expansion strategies to alleviate congestion in mid-sized cities and whether the highway agencies should look beyond to incorporate new operational and technical driven strategies in the future. Safety The existing conditions of most facilities, particularly those with inter- changes, exhibited safety deficiencies with crash rates higher than region- wide or state-wide crash rates. Poor safety performance of these facilities was primarily attributed to inadequacy of auxiliary lanes for weaving, merging, and diverging movements. This trend was observed on I-66, I-65 (Kennedy Interchange), and I-80/I-29 (East System Interchange). However, with the exception of the I-66, as well as the I-15 case studies, safety was not a primary deficiency driving the project, data were unavailable, or available safety data were questionable or did not capture a full 3-year post- construction period. Two examples that capture this last point are the I-590 Winton Interchange for which lack of intersection capacity contributed to accidents and the I-75 Reconstruction for which outdated design standards contributed to crash rates higher than the statewide average. For the I-590 Winton Interchange, accidents at the intersection between Winton Road and the I-590 northbound and southbound ramps increased by 8 percent in the 3-year period between 2014 and 2016 compared with

544 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM 2006 to 2008 (construction took place in 2012). It seems unlikely that driver acclimation to the novel configuration of a diverging diamond interchange would have contributed to the increase, since available post- construction safety data begins more than 1 year after construction completion. It is possible data accuracy or analysis consistency affected the comparison. Before-and-after traffic volumes are not available to qualify the accident data in terms of intersection usage. I-75 Reconstruction crash rates immediately post-construction (less than 1 year) are higher than the 6 years prior to construction (1.55 versus 1.13 for PDO and 0.37 versus 0.24 for injuries), although they were lower than measured during the 3-year construction period. This sample is insuf- ficient to comment on the project’s safety impact conclusively. A full 3 years of post-construction data would be needed to draw firmer conclusions on the project’s effect on safety. Most projects involving technology or demand management are de- signed to be safety neutral. This was explicitly concluded for the I-15 and US 75 ICM demonstration projects and generally understood to be true for express lane projects. Further research on the safety impacts of express lanes is an identified need, however. While the SMART 25 demonstration of the managed motorways op- erations is slated to begin in 2018, the project relies on the same technology and operational strategies as the M1 Motorway in Melbourne, Australia. The managed motorway system regulates the flow of vehicles entering congested highway corridors, limiting stop-and-go conditions and traffic instability. During the first 2.5 years of manage motorways operations on the M1, there has been a 12 percent reduction in crashes. This includes a 19 percent decrease in fatal crashes and a 10 percent reduction in serious and other crashes. Since the inception of managed motorway operations, casualty crash rates (per 100 million vehicle-kilometers traveled) on the M1 are lower than on other freeways in metropolitan Melbourne. Analysis Models Two major categories of analytical models were reported in project-level and planning-level documentation of case studies: • Travel Demand Model—Almost all studies utilized a regionally calibrated model developed by their regional or metropolitan plan- ning organization for travel demand forecasting. For instance, the Bay Area study utilized the Metropolitan Transportation Com- mission’s Travel Model One model, while the Future I-11 project utilized the travel demand model developed and maintained by the Regional Transportation Commission of Southern Nevada.

APPENDIX I 545 • Traffic Simulation Models—Microsimulation models, including VISSIM and CORSIM, were used to simulate traffic flow and de- velop mobility metrics for I-66, I-405, I-65 (Kennedy Interchange), and I-80 connected vehicle projects. Other projects, including Fu- ture I-11 and I-8/I-29, utilized models in the Highway Capacity Manual software. The I-15 and US 75 ICM demonstration combined use of both regional travel demand models and microsimulation software for analysis, modeling, and simulation exercises applied to refine application of ICM features and forecast performance. In the I-15 ICM case, the microsimulation software was also integrated into the decision support system to forecast traffic conditions up to 60 minutes in the future and provide real-time simulation and predictive analysis of incident response or congestion management strategies. Other models were also used for specific purposes, and these include Enhanced Interchange Safety Analysis Tool and Extended HSM Spread- sheets for safety analysis, toll revenue estimation model, DRAM/EMPAL— PSRC land use forecasting model and UrbanSim land use models, and EPA’s Motor Vehicle Emissions Simulator (MOVES) for emissions forecasts. PROJECT COSTS The case studies captured cost per mile or per asset estimates for each cat- egory, which are summarized in Table I-11. The costs in urban areas often depend significantly on the number and complexity of interchanges and bridges. Available cost data often do not disaggregate design components or structures. Cost per mile data may include interchanges, ramps, bridges, and other features, and therefore, the figures should only be used for plan- ning purposes on regional or representative corridor basis. Operational costs for two express toll lane facilities are also provided, however these costs are being investigated further in a separate exercise under this study.

546 NATIONAL COMMITMENT TO THE INTERSTATE HIGHWAY SYSTEM TABLE I-11 Summary of Project Costs Case Study Cost Estimates Urban Corridors/Regions Express Toll Lanes I-405 Express Toll Lanes $15.1 million/lane-mile (new ETL, ROW not included, includes ramps/interchanges) $3.1 million/lane-mile (HOV-to-ETL conversion) San Francisco Bay Area Express Lanes $3.0 million/lane-mile (HOV-to-ETL conversion) $7.5–$43.3 million/lane-mile (new ETL; lower end— construction in mostly undeveloped region, upper end— includes 2 reconstructed bridges) Utah I-15 Urban Corridor $9 million/lane-mile (new ETL, including some ramps) $2.9–$9 million/lane-mile (new GP capacity) Demand Management Demonstrations I-15 ICM Pilot $11.6 million (pilot project including planning, deployment, demonstration, and analysis) US 75 ICM Pilot $8.4 million (pilot project including planning, deployment, demonstration, and analysis) SMART 25 Managed Motorways Demonstration $10.61 million (demonstration total) $6.58 million (construction) $1.60 million (construction contingency and indirect costs) $1.77 million (integration and operations) $632,000/mile (construction) Interchange/Bridge Iway I-195 Relocation $610 million (pavement, interchange, realignment, widening, auxiliary lanes, bridge replacement) I-590 Winton Interchange $8.1 million (DDI including design, ROW, utilities, construction, inspection) I-710 Gerald Desmond Bridge $240 million (for cable stayed bridge) I-535 Blatnik Bridge $256 million (average), $188–$345 million (range) Interurban/Freight Corridors Pavement/Interchanges I-35A Waco Project 5A $182.9 million $13.65 million/mile (includes 10 interchanges) I-8 Imperial County Pavement Reconstruction $1.28 million/mile Interchanges I-80/I-29 Dual Divided Freeway $37.9 million (Nebraska Ave. interchange) $283 million (East System interchange) Future I-11 Boulder City Bypass $109 million (US 93/US 95 diamond interchange)

APPENDIX I 547 Case Study Cost Estimates I-65 Ohio River Bridges $600.3 million (I-65/I-64 Kennedy system interchange) I-85 Kia Blvd. Interchange $4.38 million (bridge structure only, including design and inspection; does not include ramps and connecting roadways) I-70 New Stanton Interchange $53.7 million (includes two roundabouts, auxiliary lanes, park-and-ride lot, bridge deck replacement, improvements to connecting roadways, and reconstruction of 1.7-mile roadway) Bridges I-80/I-29 Dual Divided Freeway $12.7 million (24th Street Bridge replacement) I-65 Ohio River Bridges $242.4 million (I-265 Ohio River Bridge) $339.3 million (I-65 Downtown Bridge) Rural Corridors Utah I-15 Rural Corridor $2.8 million/lane-mile (lane-additions) I-69 Upgrade of US 77 $2.25 million/lane-mile $1.3 million/lane-mile (pavement only) I-75 Reconstruction $136 million (multiple contracts) I-80 Connected Vehicle Pilot $5.76 million (total budget for design and deployment and 18-month demonstration) $1,260/mile (hardware cost per mile) Operational Costs I-405 Express Toll Lanes $6.7 million (2016 toll collection costs against $20.2 million in revenue; costs do not include O&M of traffic management systems) 595 Express $503,000 (2016 “toll operating expenses”) TABLE I-11 Continued

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TRB Special Report 329: Renewing the National Commitment to the Interstate Highway System: A Foundation for the Future explores pending and future federal investment and policy decisions concerning the federal Interstate Highway System. Congress asked the committee to make recommendations on the “features, standards, capacity needs, application of technologies, and intergovernmental roles to upgrade the Interstate System” and to advise on any changes in law and resources required to further the recommended actions. The report of the study committee suggests a path forward to meet the growing and shifting demands of the 21st century.

The prospect of an aging and worn Interstate System that operates unreliably is concerning in the face of a vehicle fleet that continues to transform as the 21st century progresses and the vulnerabilities due to climate change place new demands on the country’s transportation infrastructure. Recent combined state and federal capital spending on the Interstates has been about $20–$25 billion per year. The estimates in this study suggest this level of spending is too low and that $45–$70 billion annually over the next 20 years will be needed to undertake the long-deferred rebuilding of pavements and bridges and to accommodate and manage growing user demand. This estimated investment is incomplete because it omits the spending that will be required to meet other challenges such as boosting the system’s resilience and expanding its geographic coverage.

The committee recommends that Congress legislate an Interstate Highway System Renewal and Modernization Program (RAMP). This program should focus on reconstructing deteriorated pavements, including their foundations, and bridge infrastructure; adding physical capacity and operations and demand management capabilities where needed; and increasing the system’s resilience. The report explores ways to pay for this program, including lifting the ban on tolling of existing general-purpose Interstate highways and increasing the federal fuel tax to a level commensurate with the federal share of the required RAMP investment.

View the videos, recorded webcast, graphics, summary booklet, press release, and highlights page at interstate.trb.org.

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