Suppose two vehicles are approaching an intersection, one traveling in the north–south direction, and one in the east–west direction. Suppose also that they are electronically “aware” of each other, either via a vehicle-to-vehicle link or via the linkage of both vehicles to the infrastructure. Given this awareness, there is a smaller probability of a crash at that intersection, even if, for example, one of the drivers runs a red light. (Sussman 2008)
The traffic lights of tomorrow will actively manage congestion. The humble traffic signal is gaining some new responsibilities. . . . Eventually, signals will simply ask cars where they’re going, and change traffic plans accordingly. (Barry 2014)
If a modern car can be made smart enough to spot when a tire is underinflated, the oil is running low, or a brake light has failed, why not do the same for bridges . . . give them the ability to monitor their own condition and issue a warning when a problem starts to emerge? (Economist Technology Quarterly 2010)
Improving highway safety, reducing congestion, and maintaining aging infrastructure are among the challenges facing the U.S. highway system. As the above examples illustrate, there is no shortage of creative ideas for addressing these challenges in an increasingly connected world where vehicles can communi-
cate with each other and with highway infrastructure and where “smart” bridges and pavements sense problems such as cracking and alert engineers that remedial action is needed. However, extensive research, development, testing, and deployment of innovations are necessary before these ideas can become a reality. Whereas roads becoming “smart” is the next step in the evolution of highways, the roads of today are already far more sophisticated than those of earlier generations, and they might more properly be thought of as corridors that include the roadway, as well as the roadside—for illumination, signage, crash protection, and many other features. In metropolitan areas they may include sound walls to buffer noise from tires and engines, drainage systems to capture and filter runoff to protect local streams, median plantings for aesthetics and habitat, and bicycle routes. In rural areas, highways include rest areas, medians maintained with native plants and flowers, and even specially designed wildlife crossings to avoid fragmentation of habitat. These features have been added on the basis of research, development, testing, and dissemination of proven innovations.
This report discusses the Federal Highway Administration’s (FHWA’s) role in highway research and innovation and explains why this role will be critical in transforming the nation’s aging and overstressed network of highways into one that is safer, more reliable, and more resilient. These improvements will be essential in supporting the nation’s economic growth and competitiveness and enhancing Americans’ quality of life, particularly given the expected 20 percent growth in population and 80 percent growth in gross domestic product over the next 25 years (TRB 2013).
The nation’s highways today are required to meet demands not anticipated in the 1960s and 1970s, when many of these roads were planned and constructed. There are about 3½ times as many vehicles on the road as there were in 1960, and the total
number of vehicle miles traveled in a year has increased fourfold during the same period.1 In particular, highway planners and designers underestimated the rapid growth in freight movement by motor carriers and the size and weights of vehicles that would be permitted. The increased traffic volumes have not only resulted in wear and tear on highway infrastructure but also have led to congestion in many metropolitan areas, which severely hampers the movement of travelers and goods. The total cost of congestion in 2011, mostly because of 5.5 billion hours of wasted time, was estimated at $121 billion. Of this total cost, $10 billion came from wasting 2.9 billion gallons of fuel (Schrank et al. 2012). The expected 45 percent increase in freight movement by motor carriers by 2045 will place additional demands on an already stressed system (U.S. Department of Transportation 2015, 51).
Almost all the nation’s transportation fatalities (about 94 percent) occur on highways, and most involve passenger vehicle crashes (TRB 2013). About 90 people per day on average are killed on U.S. roads and more than 6,000 are injured (NHTSA 2014), even though roads and the vehicles on them are far safer now than they were 50 years ago. Despite the increasing volumes of traffic, the fatality rate, defined as the number of fatalities per 100 million vehicle miles traveled, has fallen from about 5.1 in the early 1960s to about 1.1 today.2 Further reduction in the numbers of deaths and injuries on the nation’s roads is one of the major challenges for the future, particularly as the U.S. population ages. Those 65 and older are expected to make up about 20 percent of the nation’s population in 2030 (U.S. Census
_____________________
1 National Transportation Statistics, Table 1-11, Numbers of U.S. Aircraft, Vehicles, Vessels, and Other Conveyances (http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_statistics/html/table_01_11.html); Motor Vehicle Traffic Fatalities and Fatality Rate: 1899–2003 (http://www.saferoads.org/federal/2004/TrafficFatalities1899-2003.pdf); FHWA Historical Monthly VMT Report (https://www.fhwa.dot.gov/policyinformation/travel_monitoring/historicvmt.cfm).
2 Motor Vehicle Traffic Fatalities and Fatality Rate: 1899–2003 (http://www.saferoads.org/federal/2004/TrafficFatalities1899-2003.pdf); National Highway Traffic Safety Administration Fatality Analysis Reporting System data tables (http://www-fars.nhtsa.dot.gov/Main/index.aspx).
Bureau 2014), and aging baby boomers are expected to have a profound effect on the safety of the nation’s roadways. According to one estimate, drivers over the age of 75 have a fatality rate 2½ times the national average, and for drivers over the age of 85 the rate increases to 5½ times the national average (Stutts and Potts 2006).
Public awareness of environmental issues has also increased dramatically since the 1960s, with a resulting change in expectations of how highways and the vehicles on them should interact with the environment and adjacent communities. Measures to mitigate environmental impacts have profoundly changed highway construction projects and added to their cost, as illustrated by the example of Maryland’s Intercounty Connector project in suburban Washington, D.C.; environmental mitigation costs for this project were estimated at about $15 million per mile (Skinner 2008). In addition, the increased vehicle emissions resulting from congestion raise concerns in the context of efforts to reduce the risks associated with climate change. The devastation caused by Superstorm Sandy and by the deadly mudslides in Washington State illustrates the vulnerability of parts of the nation’s highway infrastructure to extreme weather events. One of the challenges facing those responsible for the nation’s highways is to improve the efficiency and cost-effectiveness of measures to maintain, rehabilitate, and improve aging roadways while increasing the resilience of highway infrastructure to flooding and other weather-related events.
The challenges facing infrastructure owners will be compounded by revenue shortfalls for highway agencies. The nation’s 2.7 million miles of paved roads have an estimated value of $2.8 trillion (Bureau of Economic Analysis, Fixed Asset Tables, Nonresidential Detailed Estimates, as cited by Winston 2013), with a cost for maintenance and improvement that is correspondingly large. The National Surface Transportation Finance Commission estimates that long-term funding needs to maintain highways at $131 billion (in 2008 dollars) compared with revenues of only $76 billion. Improving conditions would
require $176 billion (National Surface Transportation Infrastructure Financing Commission 2009, Exhibit 2-26). The federal fuel tax, at 18.4 cents per gallon, has been unchanged since 1993; since that time the purchasing power of Highway Trust Fund revenues has declined by more than one-third (National Surface Transportation Infrastructure Financing Commission 2009). Increases in vehicle fuel economy have reduced revenues even as travel has increased, and this trend is likely to continue, with fuel economy for light-duty vehicles projected to double by 2025. In the face of unwillingness to raise user fees, funding constraints for highways appear likely to continue. Innovation cannot close all gaps, but it can help assets serve longer and perform better at lower financial, safety, and environmental costs.
The development of a wide range of advanced and affordable sensors, including Global Positioning System receivers, has opened up possibilities for transforming the way people and goods move on the nation’s roads. A connected vehicle network in which advanced technology operates the highway transportation system by electronically linking vehicles to one another and to infrastructure offers a range of benefits, including improved safety, reduced energy costs, increased roadway capacity, and greater mobility for those who cannot currently drive (Denaro et al. 2014). Some of these benefits will require fully automated vehicle operation on all roads, a challenging requirement seen by most experts as a long-term goal. Other benefits may well be realized within the next 10 years, and some are already here. In the area of safety, for example, a number of automakers now offer lane-departure warning systems in their vehicles; they alert the driver if the vehicle begins to move out of its lane on freeways or arterial roads and may even help it get back on track.
Research into connected vehicles is not limited to the United States. The United Kingdom (U.K.) government has provided funding to test driverless cars in four English cities, and the
world’s first large-scale test of driverless cars will put 100 self-driving Volvo cars on the streets of Gothenburg, Sweden, in 2017. Researchers in the Netherlands are investigating the electronic coupling of vehicles into platoons as a means of increasing road capacity and reducing energy use.3
Advanced sensors have also opened up possibilities for smart highway infrastructure. Wireless sensors mounted on a bridge, for example, can measure vibration, strain, and temperature—information that is passed to a computer for analysis and that allows continuous monitoring of the bridge’s structural integrity. Again, research in this area is not limited to the United States. The Cambridge Center for Smart Infrastructure and Construction, funded by the U.K. government through its Engineering and Physical Sciences Research Council and Innovate U.K., has developed an energy harvester that generates electricity from traffic-induced bridge vibrations, thereby allowing wireless sensors to remain in place longer without the need for charging or replacing battery packs (Cardno 2014).
The U.S. highway system stands to benefit not only from research into connected vehicles and smart infrastructure but also from the application of results from previous research initiatives. The nation has invested $223 million over the past 9 years in the second Strategic Highway Research Program (SHRP 2); the results of this research could save many lives, rehabilitate aged facilities faster with less disruption, greatly reduce congestion associated with accidents and incidents, and speed the provision of new highway capacity while preserving the environment.4 For example, the time taken to renew infrastructure can be accelerated by prefabricating bridge elements and by encouraging communication and coordination between highway agencies and utility companies to avoid unnecessary delays. While there are practical examples of the benefits to be derived from such approaches (TRB 2009b), there are also considerable
_____________________
3 Transportation Research Board 2015 Annual Meeting, Session 412: National Road Vehicle Automation Research and Demonstration Programs from Around the World.
4 SHRP 2 (http:///www.trb.org/AboutTRB/SHRP2.aspx).
barriers to innovation in the highway sector, such as the lack of incentives, strong disincentives, and risk aversion in the public sector, as described in Chapter 3. Consequently, widespread and successful implementation of SHRP 2 products is likely to require a sustained effort over an extended period. Meanwhile, the United States’ competitors are moving ahead with similar efforts. The European Union’s (EU’s) Horizon 2020 Framework program, for example, is supporting efforts to develop more efficient highway infrastructure, with the goal of achieving zero traffic disruption from inspection, construction, and maintenance by 2030.5
Whereas federal investment in U.S. research, development, and technology (RD&T) is static or declining, U.S. competitors and trading partners view enhancing their transportation systems through research as a strategic investment. The EU, for example, plans to spend more than €6 billion (about $7.1 billion) on transportation research during the 7-year period from 2014 through 2020. This investment in innovation for “smart, green and integrated transport” also aims to enhance the competitiveness of European transport manufacturers and service providers (McKinnon 2015). The U.S. Department of Transportation’s annual research budget (U.S. Department of Transportation 2013), along with transportation RD&T funding by states, is about $1.2 billion across all modes, or roughly equivalent to that of the EU (see Table 3-1, and related discussion). The EU funding, however, is on top of all transportation RD&T by all its member nations.
As Congress prepares to reauthorize the Moving Ahead for Progress in the 21st Century Act (MAP-21), which funds federal highway and transit investments, lawmakers will need to make
_____________________
5 Horizon 2020 Work Program 2014–2015: Smart, Green and IntegratedTransport (http://ec.europa.eu/research/participants/data/ref/h2020/wp/2014_2015/main/h2020-wp1415-transport_en.pdf).
decisions affecting the nation’s ability to improve its highways in response to demands for economic growth and competitiveness, health and safety, resilience, access, and environmental protection. Chapter 2 discusses the role of the federal government, operating through FHWA, in supporting the innovations that have transformed the highways of the 1960s and 1970s into the safer, faster, and greener highways of today. Chapter 3 describes the federal role in the broader context of the nation’s organizationally complex highway RD&T endeavor, and Chapter 4 examines FHWA’s RD&T role in meeting future challenges.
