To discover some of the technologies that may become mainstream tools for civil engineers within a few years, CE News invited researchers from selected organizations to complete a brief online survey about their work. The following summaries offer a glimpse of the broad range of solutions being investigated for transportation infrastructure, stormwater management, water quality, environmental protection, and other pressing problems.
Bayesian Networks for Infrastructure Seismic Risk Assessment & Management
Researcher: Armen Der Kiureghian, Taisei Professor of Civil Engineering, University of California, Berkeley
Description: We are developing the prototype of a Bayesian network-based decision support system for post-earthquake emergency response and risk management of infrastructures systems. One application is to the California high speed rail system.
Importance: This project uses advances information technology tools to address urgent societal needs. The Bayesian network is used as a tool for information processing and in support of decision making to minimize risk from natural hazards.
Current status: 60 percent complete
Expected benefit: Hope soon after to demonstrate the prototype
Water Quality Benefits of the Permeable Friction Course
Researcher: Michael Barrett, research associate professor, University of Texas at Austin
Description: The Permeable Friction Course is a 2-inch-thick porous asphalt overlay placed on top of conventional asphalt or concrete pavements. It is used in many parts of the United States and around the world because it reduces splash and spray associated with vehicles, improves visibility, and reduces hydroplaning. The objective of our work is to document the effect it has on the quality of highway runoff. Monitoring to date has demonstrated that this paving material reduces the pollutants in highway runoff by up to 90 percent. The reduction can be attributed to the removal of pollutants within the pavement as well as reducing the source of pollutants by eliminating the splashing that would wash pollutants from the engine compartment and underneath the vehicle. Ongoing research is directed at determining how long these water quality benefits persist. The documentation of these benefits should result in the approval of this material as a permanent BMP to improve runoff quality.
Importance: Departments of transportation (DOTs), as well as municipalities, have stormwater permits that require reduction in pollutant discharge. This work will allow DOTs to comply with these water quality requirements using a material already in widespread use for safety reasons and without the purchase of additional right-of-way for construction of expensive structural treatment systems. It is particularly useful in urbanized areas, where there may be no space available for stormwater management.
Current status: End game
Expected benefit: Immediately
Floating Sensor Network
Researcher: Alexandre Bayen, assistant professor, University of California, Berkeley
Description: The Floating Sensor Network project (http://float.berkeley.edu) is building a water-monitoring system that can be deployed in estuarine environments and rivers, and can be integrated into existing water-monitoring infrastructure. The Floating Sensor Network team will build 100 motorized drifters, which are communication-enabled and integrate numerous sensors, including GPS, temperature, and salinity. The fleet will be deployable rapidly in response to unanticipated events such as floods, levee breaches, and contaminant spills. The team is also working on hydrodynamic models and inverse modeling algorithms to integrate these measurements in the models. Jointly with the Lawrence Berkeley National Laboratories and the California Department of Water Resources, the team is developing a computational infrastructure that will run online and integrate measurements from static sensors (for example, U.S. Geological Survey permanently deployed sensing stations), mobile measurements, and any other data feed available to estimate river flow and contaminant propagation in real-time. The results will be available to users in the form of “water maps” that show the motion of water in real-time, and corresponding transported quantities (such as salt).
Importance: Water managers need to track the movement of water, salinity, and other contaminants in complex networks of channels like deltas or estuaries. Whether in emergency situations such as a levee failure, flood, or contaminant spill, or for management efforts such as maintaining the freshwater channel in Northern California’s Sacramento-San Joaquin Delta, it is important to understand “where the water is going.” Permanently placed sensors are important tools, but they cannot be placed everywhere on a large complex network of water or levees, and they don’t track water as it moves.
Current status: Mature
Expected benefit: Next year
Manufactured Sands for Concrete Pavements
Researcher: David Fowler, Joe J. King Chair in Engineering, University of Texas at Austin
Description: Natural sands are becoming in short supply in some parts of Texas. There is a need to be able to use manufactured fine aggregate (MFA) for constructing concrete pavements. This project will investigate the needed aggregate properties, the mixture proportions for the concrete, finishing methods, and the surface friction of pavement concrete made with MFA. For carbonate MFA, the skid reistance may be inadequate, and methods to overcome the problem will be investigated. The benefits of the project will be specifications for using MFA, quality control tests, and methods to ensure that adequate surface friction is obtained. The benefits will be the ability to use MFA in concrete pavements which will eliminate the need to transport natural sands for long distances which is uneconomical.
Importance: It is important that concrete pavements be constructed as economically as possible. In the future when natural sands are depleted, it will be essential that local materials, e.g. MFA, be used for pavements if at all possible.
Current status: Materials testing and surface friction testing phases
Expected benefit: Within a year or so after the conclusion
TH-36 Full Closure Construction: Evaluation of Traffic Operations Alternatives
Researcher: John Hourdos, assistant proffessor, adjunct, University of Minnesota
Description: Th-36, a major arterial northeast of Minneapolis-St. Paul, Minn., was reconstructed during the summer and fall of 2007. Mainly because of budget constrains, Mn/DOT decided to employ a five-month full road closure (FC) for this project. This full closure was the first of this size in Minnesota and attracted the attention of engineers and the public. This project’s objective was to evaluate the full-closure alternative and compare it with a hypothetical, partial closure through simulation. Additionally, this project followed the construction closely to collect experiences, lessons, and performance indicators, compiling a “lessons learned” document to assist Mn/DOT engineers in future projects considering full closure.
Importance: Full road closures as a construction alternative promise to reduce road reconstruction costs for the agency and the public. Being new and untried, engineers encounter difficulty in planning such projects, while the public is very sensitive to such large interruptions in the network. Learning both from experimentation and by observation is the best combination.
Current status: Currently refining Full Closure Guide document and final report
Expected benefit: Already have benefited since the construction project and the evaluation report helped demystify full road closures.
Researcher: Alexandre Bayen, assistant professor, University of California, Berkeley
Description: Mobile Millennium (http://traffic.berkeley.edu) is a research project, which includes a pilot program for a traffic monitoring system that uses GPS inside phones to gather traffic information, process it, and distribute it back to the phones in real time. The pilot program was launched by UC Berkeley, Nokia, and NAVTEQ from the Berkeley campus on Nov. 10, 2008. It ran for exactly 12 months. During that time, more than 5,000 users downloaded the Mobile Millennium traffic client on their phones. The download feature of the pilot is now finished. The early users are free to keep using the software. Soon, NAVTEQ will release a commercial version of the software, which will also feed the Mobile Millennium system with cell phone data. The Mobile Millennium system currently operational at UC Berkeley integrates numerous feeds into traffic models, which broadcast highway and arterial traffic information in real-time. The feeds include data obtained from GPS-enabled mobile phones, all of the San Francisco taxis (through GPS), radars, loop detectors, and historical databases.
Importance: The mobile internet is changing the face of traffic monitoring at a rapid pace. In the last five years, cellular phone technology has bypassed several attempts to construct dedicated infrastructure systems to monitor traffic. Today, GPS-equipped smartphones are progressively morphing into an ubiquitous traffic-monitoring system, with the potential to provide information almost everywhere in the transportation network. Traffic information systems of this type are one of the first instantiations of participatory sensing for large-scale cyberphysical infrastructure systems.
Current status: Mature
Expected benefit: It already has.
Methods of Evaluating the Redundancy of Steel Bridges
Researcher: Karl H. Frank, The Warren S. Bellows Centennial Professor in Civil Engineering, The University of Texas at Austin
Description: Evaluation of the behavior of twin box girder bridges when one of the fracture critical flanges fractures. The project includes development of analysis tools to predict behavior and full-size tests of a bridge.
Importance: The results allow the owner to assess the criticality of these types of bridges and adjust the inspection requirements based on the expected behavior of the bridge rather than arbitrary inspection requirements.
Current status: Completed
Expected benefits: Within the next year.
I-35W Bridge Monitoring and Data Interpretation
Researcher: Catherine French, Institute of Technology Distinguished Professor, principal investigator, Civil Engineering, University of Minnesota
Description: The new I-35W bridge was instrumented with “smart bridge technology.” The purpose of the instrumentation is to monitor the performance of the structure during service. Instrumentation includes vibrating wire and resistive strain gages and thermistors in the foundation, bridge piers, and superstructure. The bridge superstructure also incorporates fiber optic sensors, string potentiometers, and accelerometers. Most of the instrumentation (e.g., vibrating wire strain gages, fiber optic sensors, and string potentiometers) is considered “static” instrumentation. The accelerometers are the primary dynamic sensors and are to be used to provide information regarding the deflection of the individual box sections. In addition, Span 2 of the south-bound exterior box contains a suite of 14 accelerometers to evaluate the dynamic modes and vibrations of the box. All of the instrumentation is located in a permanent position, with the exception of the 14 accelerometers that might be repositioned based on the bridge response and the information sought. It is anticipated that the instrumentation will be read four times per day, with the dynamic data read over the course of 15 minute intervals. At four times during the course of the project, a dynamic data acquisition system will be provided by the subcontractor to investigate the dynamic nature of the bridge with the fiber optic system. The role of the University of Minnesota is to evaluate the data to be obtained from the instrumentation and to provide an annual report to the Minnesota Department of Transportation regarding the performance of the bridge.
Importance: The results of this project will be used for several purposes. First, the instrumentation in the bridge will be used to further the understanding of concrete box structures in Minnesota. In particular, we will gain a better understanding of how the I-35W Bridge responds to environmental (thermal) loading. In addition to measuring the responses of the bridge to thermal loadings, we will also be measuring temperatures internal to the bridge structure at a number of locations to see if the thermal gradients used for design are appropriate for these types of structures in Minnesota. The second area of interest is that we will be learning more about methodology for structural health monitoring of bridges in Minnesota. There are a number of instrumentation systems deployed in this bridge. The data from these systems and the reliability of these systems can be compared and contrasted to help determine which instrumentation systems are most effective for long-term monitoring of bridges.
Current status: In progress
Expected benefit: The industry is already benefiting from this project. The results of a truck test have been presented to show that the bridge is behaving as it should under substantial vehicle loading. Benefits related to environmental loadings will not be realized for another year or two. Likewise, benefits from comparing data quality, usability, and sensor reliability won’t be available until the end of the project (or in about two to three years).
Full-Depth Precast Concrete Bridge Deck — System Phase II
Researcher: Catherine French, Institute of Technology Distinguished Professor, principal investigator, Civil Engineering, University of Minnesota
Description: The Minnesota Department of Transportation (Mn/DOT) Precast Composite Slab Span System (PCSSS) is an effective bridge system for short- to medium-span bridges (20 to 60 feet). The system consists of a series of 6-foot-wide, inverted, precast T-sections that are placed between supports. Cast-in-place (CIP) concrete is placed on top of the precast sections to form a monolithic slab span system. Engineers use reinforcement at the webs of the Ts and also place reinforcement cages between the precast webs in order to intersect any longitudinal cracks that may develop above the joint and between the adjacent precast flanges. Several of these systems have already been constructed and have been in service for up to three years. It is important to document the performance of these systems in the field by mapping any cracks that have developed and to correlate the cracks to the potential joint regions. Researchers will document the surface cracks on four of the existing PCSSS bridges, and will also review a sampling of cores taken from the bridges to evaluate the potential development of reflective cracks. The cores will be taken above the longitudinal joints and between the precast flanges. One of the early implementations of this bridge system (Center City Bridge) showed the development of cracking above the longitudinal joint, between the precast sections, and also at the pier. These cracks were detected with limited instrumentation in the CIP portion of the bridge and appear to be the result of thermal gradient effects. The strains at these locations have been observed to increase over time. As part of this project, researchers will continue to monitor the sensors in the Center City Bridge. In addition, the investigators will review and comment on the latest design methods implemented by Mn/DOT for the PCSSS bridges, including the concept of designing the bridges as a series of simple spans rather than considering the effects of restraint moments.
Importance: Because these systems represent a new design concept in the United States, it is important to evaluate the performance of these initial field implementations, as well as evaluate proposed modifications to the design of new systems. This project is important to ensuring that these systems are exhibiting good durability. If any problems are identified with the systems in the field, improved detailing procedures can be proposed to ensure improved performance of future systems.
Current status: Mapping of the cracks is currently underway. It is planned to revisit the bridges in the Spring of 2010 to monitor any changes in the observed cracking. As the performance of the systems and proposed design revisions are evaluated, recommendations will be made regarding suggested changes to improve performance throughout the project.
Expected benefit: Based on the findings of this study, the researchers will propose potential modifications to the design process or detailing to further improve the performance of PCSSS bridges. Mn/DOT will likely begin to benefit around Fall 2010, after we have had the opportunity to take the cores from the field and analyze them and do a second set of crack mappings. At that point, we should have a better understanding of the nature of the cracking being observed in the field and its anticipated effect on the durability of the bridges, and hopefully, some suggestions for how to mitigate the cracking in future implementations.
SMART-SIGNAL: Systematic Monitoring of Arterial Road Traffic and Signals
Researcher: Henry Liu, assistant professor, principal investigator, Civil Engineering, University of Minnesota
Description: Performance monitoring for arterial traffic control and management is an area of emerging focus in the United States. Although many existing signal control systems are capable of generating data to support performance assessment, most do not make it easy for the managing agencies to prioritize improvements and plan for future needs. The 2005 and 2007 National Traffic Signal Operation Self-Assessment Survey indicated that a majority of agencies involved in the operation and maintenance of traffic signal systems do not monitor or archive traffic system performance data in an effort to improve their operation, largely due to the expense of manual data collection and performance measurements. A University of Minnesota research team developed an arterial data collection and performance monitoring system, named SMART-SIGNAL (Systematic Monitoring of Arterial Road Traffic and Signals). The SMART-SIGNAL system is capable of generating both intersection and arterial performance measures in real-time. At the single intersection level, SMART-SIGNAL can monitor the maximum queue length on a cycle-to-cycle basis, from which other performance measures such as intersection delay and level of service can be calculated accordingly. At an arterial level, SMART-SIGNAL can report travel time, speed, and average number of stops in real time. SMART-SIGNAL does not require additional detector instrumentation and it works with both inductance loop detectors and video detectors. The developed algorithms can work with the detector input data from standard vehicle-actuated signalized intersections. SMART-SIGNAL has been implemented on 11 intersections along France Ave. in Hennepin County, Minn., and six intersections along TH 55. The system was evaluated independently by a transportation consulting firm with successful results.
Importance: The project is important because it helps to automate the process for performance measurement and optimization of traffic signal systems. In the current practice, performance measurement of traffic signal systems is manually conducted, and it is time-consuming and expensive. In addition, due to the high cost associated with manual data collection, traffic signal re-timing is usually performed every three to five years, and in many metropolitan regions traffic signals are operated sub-optimally because of changing traffic patterns. The success of this project will fill in this gap and significantly reduce the operations and maintenance of traffic signal systems.
Start/End: 2009 (this phase)/2011
Current status: In progress
Expected benefit: The industry has already started to benefit from this research. The city of Pasadena has decided to implemented the SMART-SIGNAL system on six intersections of their roadways.
Assessment and Maintenance of Stormwater Best Management Practices
Researcher: John Gulliver, professor, principal investigator, Civil Engineering, University of Minnesota
Description: The 1987 Amendments to the Clean Water Act required implementation of a two-phase program to regulate discharges of stormwater. The regulations were developed in two parts, in three separate programs: 1) Municipal Separate Storm Sewer Systems (MS4s), 2) Construction Activities, and 3) Industrial Activities. Phase I focused on large construction sites, 11 categories of industrial facilities, and major metropolitan MS4s (in Minnesota, this was only St. Paul and Minneapolis). Phase II expands these regulations to include smaller construction sites, industrial activities in small municipalities, and municipalities of larger than 10,000 people. New permits for the Phase II program were filed in March 2003, starting the first five-year implementation cycle. Various levels of government will spend hundreds of millions of dollars on implementation of stormwater treatment practices over the next 20 years. Guidance is needed, and the document “Assessment of Stormwater Best Management Practices” was developed. Visual inspection and testing have been developed as a potentially time- and cost-saving concept that will be advocated when appropriate. They involve making selected investigation of performance, without requiring that input water actually be stormwater runoff. The methodology currently under development includes four levels of assessment, in increasing order of effort: 1) visual inspection, 2) infiltration testing, 3) simulated flood testing, and 4) monitoring. Levels Nos. 1, 2, and 3 were developed for the assessment document, but require more investigation to establish well-documented procedures for all major applications. The advantage to visual inspection and testing is that the appropriate level of effort can be expended in assessing the performance of a given stormwater best management practice (BMP). Monitoring is the most intensive, and is advocated when required to obtain the desired results and when testing is not feasible. The difference in cost is significant. Monitoring (Level No. 4) costs are approximately $100,000 per year per site, with two years or more required to obtain a sufficient number of storms. Level No. 3 testing is between $1,000 and $10,000 per site for infiltration testing up to $50,000 per site for the testing of underground proprietary devices, and is completed in one season with improved accuracy for selected parameters, such as removal efficiency. Level No. 2 testing is estimated to cost between $1,000 for a small site and $10,000 for a larger site. Visual inspection (Level No. 1) is estimated to cost $300. For example, if we have 1,000 rain gardens in Minnesota, the cost to monitor (Level No. 4) all of them would be approximately $100 million per year. Level Nos.1 and 2 assessments would be more appropriate for the multitude of rain gardens in Minnesota. These choices and the assessment methods developed will be disseminated through courses at the University of Minnesota and through short courses given through the University Extension Service. Of particular interest are MS4s, which includes separate stormwater treatment practices owned or operated by a state, city, town, borough, county, parish, district, association, flood control, and drainage districts, or similar entities. These entities are now implementing six-part Storm Water Pollution Prevention Programs, each of which includes: 1) public education and outreach, 2) public participation/involvement, 3) control of illicit discharges, 4) construction site runoff control, 5) post-construction site runoff control; and 6) pollution prevention/good housekeeping. The implementation of the Phase II NPDES permits has these MS4s concerned. They are not sure what to do, are not sure of the science and engineering that is behind many stormwater BMPs, and are not sure of the liability of implementing the requirements specified by the Minnesota Pollution Control Agency (MPCA). Considerable help has been provided in the Minnesota Stormwater Manual and the document Assessment of Stormwater Best Management Practices, both of which are on-line documents whose publication was funded by the MPCA. Because of the large investment that is going into implementing Stormwater BMPs, and the fact that this investment will continue, more help is needed in demonstrating the methods developed in previous projects, in monitoring unknown aspects of stormwater that are crucial to design, operation and maintenance of stormwater BMPs, and in determining the groundwater pollutant concentrations that result from infiltrating polluted stormwater to surface aquifers. The proposed project will assist MS4s by expanding the scope of the on-line document, “Assessment of Stormwater Best Management Practices,” to include effective maintenance procedures. In addition, three case studies incorporating stormwater BMPs into load-based predictions for watersheds will be undertaken, one for water temperature in Miller Creek, Duluth, and one for water temperature in the Vermillion River. The suspended solids size distribution and organic content will be monitored for various soil types, land uses and seasons for the state of Minnesota. Finally, the impact of infiltrating polluted stormwater into the groundwater system will be assessed both locally and on a regional metropolitan basis. The result will be improved assessment of stormwater BMP effectiveness, implementation of maintenance procedures when a stormwater BMP is not performing well, and improved stormwater BMP integration into watershed TMDL studies. Finally, if assessment has found that a stormwater BMP is not achieving the desired result, maintenance/renovation should be prescribed. The appropriate maintenance procedures will be incorporated into the on-line document, “Assessment of Stormwater Best Management Practices.” The document will then be a one-stop location for the assessment, maintenance and renovation of stormwater BMPs. The benefits of the proposed project would outweigh the costs by improving the cost-effectiveness of stormwater treatment evaluation and maintenance. The proposed project will continue its intensive outreach effort, providing workshops on visual inspection procedures, educating undergraduate and graduate students, and informing the local and national professional community of the state of Minnesota’s efforts in stormwater BMP assessment.
Importance: The wear of brake pads and tires, dirt brought into the street, and the associated chemicals end up in our rivers, estuaries and lakes. Organizations have begun to require that this urban runoff pollution be treated before reaching receiving waters, and new techniques to assess and maintain stormwater treatment practices are required for these activities to be more cost-effective. This is especially important for the low-impact development practices that are being advocated by many in the industry. A multitude of these relatively small practices require that we develop corresponding performance assessment and maintenance methods.
Current status: Complete
Expected benefit: Industry is currently benefiting from the findings. The four-level assessment program is advocated by many in the U.S. EPA and is generally utilized in Minnesota and other states to provide a cost-effective methodology to meet performance assessment goals of stormwater treatment practices.
Assessment of Underground Stormwater Management Devices on the Water Quality of Runoff
Researcher: Omid Mohseni, lecturer, principal investigator, St. Anthony Falls Laboratory, University of Minnesota
Description: The objectives of this research were threefold: to investigate the feasibility and practicality of field testing to assess the performance of underground devices used for stormwater treatment in urban areas; evaluate the effects of sediment size and stormwater flow rate on the performance of four manufactured devices; and to develop a universal approach for predicting the performance of a device for any given application. Field testing that used a controlled and reproducible synthetic storm event that contained sediment of a fixed size distribution and concentration fed to pre-cleaned devices led to the development of uniform performance models. The results of this project show that controlled field tests are a practical, robust, and accurate means of determining an underground device’s performance, based on solid size distribution and density of the influent, in addition to water discharge and temperature. This premise was successfully verified in field tests on four devices and in laboratory tests on two devices. The resulting protocol and results of testing will be a useful tool for consultants, manufacturers, local governments, and state agencies for selecting, sizing, and evaluating stormwater treatment technologies to protect water resources.
Importance: Data collected and tests done on these devices prior to our research had exhibited contradictory results. Therefore, nobody really knew how well these devices were functioning and whether they were effective as stormwater treatment devices. We approached the problem differently and developed a laboratory test method as well as a field test method which could reproduce similar results by anyone conducting these tests anywhere in the world. In addition, we introduced a performance function which could be used to determine how these devices might work at flows or for stormwater suspended sediments not tested in the laboratory. Both the American Society of Civil Engineers’ Environmental & Water Resources Institute (ASCE/EWRI) and the ASTM are in the process of adopting the test method developed. They have been incorporated in the ASCE/EWRI draft verification guidelines of the manufactured BMPs and in the ASTM standard test method for hydrodynamic separators that subcommittee members voted on in November.
Current status: Complete; final report published
Expected benefit: Manufacturers and other researchers have started using the mass balance method to test these devices.
Toward a Transparent Earth
Researcher: Steven D. Glaser, professor, University of California, Berkeley
Description: This proposal presents a plan to install and operate a permanent seismic observatory illuminating the volume of the Homestake Mine, at the deep underground scientific and engineering laboratory (DUSEL), from all six possible directions. We have chosen the Homestake DUSEL site because it offers a unique opportunity — the large volume of mine working of the deepest mine in North America is surrounded and underlain by literally thousands of open bore holes, which can affordably be instrumented with geophones and accelerometers. There are many technical implications of the observatory beyond direct imaging of rock mechanics mechanisms, e.g.: Underground and Mine Safety — more quantitative methods to quickly locate any potential dynamic rock failure within mine will be an immediate benefit. Homeland Security of Underground Facilities — use reciprocity to study methods of detecting and characterizing underground structures and activity. Study explosions associated with coal mining activity in Wyoming as contribution to nuclear monitoring program. Global Seismology — take advantage of location and depth of array to assess maximum frequency content of teleseismic phases.
Importance: We envision a seismic array that allows the community to image rapid dynamic changes in the rock mass. For instance, we will be able to estimate seismic parameters of events associated with de-watering, excavation, and various rock mechanics experiments, and estimate source kinematics caused by activity within or near the mine. From the damage location of a seismic event determined by the array, the rock mass could be excavated to find the source damage in the rocks. If found, a direct connection can be made between a given damage process and seismic waves generated. This knowledge would be applicable to all sites, and help answer important questions concerning the energy budget of fracture growth and dynamics, local frictional behavior within a rock mass, seismic scaling laws, and the interpretation of seismic moment tensors.
Current status: Installation of equipment and data evaluation
Complex Infrastructure Risk Assessment and Management: Resilience & Sustainability of Critical Infrastructure Systems in the Sacramento-San Joaquin Delta Region
Researcher: Robert Bea, professor, Department of Civil & Environmental Engineering, University of California, Berkeley
Description: Contemporary infrastructure, the systems necessary to provide sustainable services within the nation’s power, transportation, waste management, water, and telecommunication sectors, has become very complex; that is, adaptive, interdependent, unpredictable, nonlinear, and dynamic. This research seeks to discover new fundamental methods (through interdisciplinary research) to assess and manage the resilience and sustainability of such complex systems (termed I3CIS). These methods will facilitate the characterization of both resilience and sustainability by addressing multi-infrastructure, multi-physics, multi-scale (spatial, temporal), and multi-resource phenomena that impact the likelihood of these systems failing to achieve acceptable resilience and sustainability, as well as the associated consequences.
Importance: The recent failures of the flood defense, evacuation, and recovery systems for the Greater New Orleans area during and following Hurricane Katrina have demonstrated unequivocally that human, organizational, social, cultural, and political factors play dominant roles in assuring the reliability of Interdependent Complex Infrastructure Systems (ICISs). This research proposes a collaborative interdisciplinary study to create, validate, and apply new Risk Assessment and Management (RAM) methods to assess and improve the design, operation, and maintenance of ICISs. Since human beings manage and operate within complex organizations, to fully understand the behavior of ICISs requires that we integrate the physical/environmental sciences (technology) with the social sciences (human and organizational factors).
Current status: Testing advanced RAM models in field pilot project
Expected benefits: Initial developments have been published and presented to industrial and governmental organizations.
Subsurface Drainage Manual for Pavements in Minnesota
Researcher: John Nieber, professor, principal investigator, Bioproducts/Biosystems Engineering, University of Minnesota
Description: Subsurface drainage removes excess moisture from the base course and the subgrade of highways, thereby increasing the overall strength of the pavement structure. Previous research has shown conclusively that effective subsurface drainage provides cost-effective benefits in terms of pavement maintenance and replacement costs. There are many factors that need to be considered in the design of subsurface drainage systems, and because of the tremendous benefits of subsurface drainage it is very important to design the drainage system correctly. Several reports have been published nationally that provide guidance to designers of subsurface drainage systems, but these reports are not specific to the conditions of the north central region, nor are they ready guides. The objective of this project was to develop a design and maintenance manual for pavement subsurface drainage systems in Minnesota. The manual is intended for engineers and managers involved in pavement design, construction, and maintenance decisions. A guide for evaluation of highway subsurface drainage needs and design of subsurface drainage systems for highways has been developed for application to Minnesota highways. The guide provides background information on the benefits of subsurface drainage, methods for evaluating the need for subsurface drainage at a given location, selection of the type of drainage system to use, design of the drainage system, guidelines on how to construct/install the subsurface drainage systems for roads, and guidance on the value of maintenance and how to maintain such drainage systems.
Importance: Subsurface drainage of paved roads is an important part of extending the pavement longevity while reducing the initial cost and maintenance cost of installed pavements. Procedures for designing and installing drainage facilities for pavements are generally known to hydraulics design personnel in highway departments and in consultancies, but they are not widely understood or appreciated among county engineers and many other state highway engineers. Providing guidance to a broader audience on how to conduct designs, installations and maintenance will help to promote the wise use of subsurface drainage for highways.
Current status: Complete; final report published
Expected benefit: The industry cannot benefit from the results of this project until the guidance document is adopted for use by design engineers at different levels. Once it is used it should provide for development of a common knowledge among highway engineers across the state and thereby it is expected that pavement systems will benefit.
Researcher: Yetkin Yildirim, director, Texas Pavement Preservation Center, The University of Texas at Austin
Description: To improve new applications in the area of Pavement Technology
Importance: Improves public safety, saves public money, improves pavement performance
Current status: On going; three patents are pending
Expected benefits: Immediately
Evaluation of Active, Lighted Pavement Markers To Improve Safety Along Houston METRO’s Light Rail Line
Researcher: Anthony Voigt, research engineer, Texas Transportation Institute
Description: This project is an evaluation of the use of lighted pavement markers in parallel to an intersection stop bar for intersection approaches in Houston, which lie along a light rail line. The line of pavement markers is active with a red light (light emitting diode) displayed from each marker during the red interval of the traffic signal. The intended impact of the pavement markers was to reduce red light running violations and crashes on the intersection approach to an arterial with an at-grade light rail line within the median of the street. A before-and-after study was conducted to determine changes in crashes, red light running violations, and right turn on red violations. From the analysis results, it was determined that the lighted pavement markers appeared to reduce right turn on red violations. Furthermore, red light running violations appear to be slightly reduced.
Importance: Passenger vehicle versus light rail vehicle crashes can be very dangerous, costly, and disruptive to the transport of thousands of individuals. If an innovative traffic control device could be used to warn drivers of the approach of a light rail vehicle on an at-grade intersection, then crashes may be avoided.
Current status: Field Evaluation
Expected benefits: Interim results already being disseminated.