U.S. Department of Transportation
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A human system integration (HSI) measurement tool is needed to model the human factors maturity and readiness of operational capabilities comprising the Next Generation Air Transportation System (NextGen) for transitioning from research and development to implementation. NextGen poses impressive transitions of new technologies, concepts, and automation needed to handle projected increased future traffic demand placed on the National Airspace System (NAS). These transitions will occur both in the aircraft and with air traffic control (ATC) and involve dramatic delegation for spacing and separating aircraft to pilots from controllers. The transitions will also challenge the architects of NextGen in determining how new sophisticated automation and associated procedures can efficiently handle more traffic while avoiding overload on the pilot and controller.
The HSI measurement tool would classify and model the portfolio of NextGen operational capabilities in order to measure the level of HSI maturity of a new technology or application during its development. Previous human factors research reported on a set of some 20 attributes used to assess human factors risk in development of air traffic management systems (see http://www.hf.faa.gov/Portal/techrptdetails.aspx?id=1646). The classification should demonstrate the mutual interdependencies and interactive constraints among a heterogeneous set of operational capabilities. The classification would identify research issues resulting from these constraints on the human operator and the implications for technology or automation maturity being developed.
Research is needed to develop and validate anchors by which to measure and model the maturity of human factors considerations associated with NextGen operational improvements. The model could start with Technology Readiness Levels, or Levels of Maturity as described in the FAA System Engineering Manual (see paragraph 4.2.6.2.3 on FAA System Engineering Milestones at http://www.faa.gov/about/office_org/headquarters_offices/ato/service_units/operations/sysengsaf/seman/SEM3.1/Section%204.2%20v3.pdf). This research would develop the tool for use in benchmarking and transitioning NextGen capabilities across all stages of development. The tool could also provide an important human factors technique in the evaluation during operational testing.
By defining a network of key HSI attributes, this research will provide a new framework for defining, assessing, and understanding the maturity of individual operational capabilities. The research will extend this perspective to examining the interoperability of capabilities as aircraft progress through different phases of flight, as described in the NextGen Implementation Plan in relation to technology, automation, and procedures (see http://www.faa.gov/about/initiatives/nextgen/media/ngip.pdf). This provides a unique nomological view on both major and subtle changes in the demands on pilot and controller situation awareness, workload, and communications in relation to the envelope of effective and efficient human performance.
This research aligns with OMB-OSTP memorandum M-09-27 and its General Science and Technology Program Guidance that "Agencies should develop 'science of science policy' tools that can improve management of their research and development portfolios and better assess the impact of their science and technology investments."
The output of the Phase I research effort is to spawn an innovative approach modeling the contribution of HSI in measuring the maturity of NextGen research capabilities for transition to implementation.
Travel time and origin-destination data and characterization are key to System Performance Measurement. The objective of this project is to develop an inductive loop based technology for monitoring the travel time and origin-destination performance of vehicles that augments a Bluetooth based travel time system now under development.
This technology is intended to complement the Bluetooth based travel time and origin-destination technology1 being developed under a separate SBIR project2 and being independently explored by various universities and state DOTs Inductive loop signature identification and re-identification has several advantages over and disadvantages under the Bluetooth based technology. To their advantage, loop signatures characterize almost 100% of the vehicles traveling over them while Bluetooth technology characterizes none of them. Bluetooth always correctly re-identifies vehicles while loops may mismatch or miss signature matches. Loop signature technology works best where there are already preexisting loops for either signal control, weigh in motion systems, permanent count stations or speed measurement with only minimal additional loops needed for completing the system performance measurement network while Bluetooth sensors can be deployed in any location with power access and many without power access. Loops give a very accurate estimate of total vehicle count while Bluetooth only gives a 5 to 10% sample. Because of this, the two systems are complementary rather then competitive. Together, they would allow a very accurate estimate of surface transportation system performance which is a key USDOT goal.
The objective of measuring travel time has several aspects. First, the vehicle signature must be accurately yet anonymously sensed at the first location. For the purposes of this SBIR "accurately sensed" includes providing an accurate classification of the vehicle according to the FHWA classes3 based on the vehicle signature. Second, the vehicle must be accurately yet anonymously sensed at a second location. Third, communications must make it possible to accurately match the two loop signatures and the elapsed time between the two identifications while providing anonymity to the driver. Fourth, it must be possible to assemble these identifications into travel time and origin-destination data for purposes of developing System Performance Measurement. This must be done in near real time if the data is to be available for real time transportation systems developed with FHWA funding such as Adaptive Control System (ACS) and ACS-Lite.
1Wasson, Jason S.; Sturdevant, James R.; Bullock, Darcy M., "Real-Time Travel Time Estimates Using Media Access Control Address Matching", Institute of Transportation Engineers, ITE Journal, June 1, 2008.
2FHWA SBIR 08-FH2, "Research and Development of Anonymous Traffic Probes for Travel Time and Origin-Destination using Bluetooth IDs."
3Traffic Monitoring Guide, FHWA-PL-01-021, http://www.fhwa.dot.gov/ohim/tmguide/index.htm.
The software for processing the unique signatures, tracking the travel time measurements from the unique signatures, and communicating them from location to location may be proprietary. However, to make the system useful to a wide variety of Transportation Management Centers and Real Time Control Systems such as ACS and ACS-Lite, there must be an open source software package which can take these signatures and corresponding vehicle classifications and calculate travel time and origin-destination data as well as providing information availability to the local Advanced Transportation Controllers. The open source requirement is to ensure full and continued evaluation of the algorithms. Communications should be encrypted with the GNU OpenPGP to facilitate data privacy and prevention of tampering.
http://www.gnupg.org/
http://www.ietf.org/rfc/rfc4880.txt
In Phase I, field tests must demonstrate that the technology can successfully sense and track vehicles between two points with vehicle classification. Statistical characterizations of the number of vehicles that can be successfully identified at the first location and then re-identified at the second location must be made. These should be compared to ground truth against the total vehicle population traveling between the two points. This will demonstrate the potential of the new technology. The loop signature sensor hardware may be a device previously developed by the SBIR proposer or one of its partners or may be developed or developed further under this project.
Phase II would develop the new or enhanced technology and then demonstrate the prototype at a sequence of intersections and freeway locations. The technology should be evaluated at a sequence of instrumented stations for establishment of a rigorous statistical measurement of the accuracy of the technology against "ground truth" in the real world during a variety of weather conditions. The University of California-Path, Virginia Tech, Purdue, and Texas A&M have sensor test facilities which might be suitable for such tests. A demonstration of the basic effectiveness of the concept would also be conducted at the TFHRC intelligent intersection. (note: The TFHRC intersection uses 2070 ATC units so use of another class such as regular ATC's or NEMA controllers might require demonstration of one of the alternative sites. Compatibility with one of 1) 2070 ATC, 2) ATC or 3) NEMA standard traffic signal controller would be part of the Phase II test.
NOTE: The specific technology(ies) for the communications have not been specified. Several traffic signal control companies and traffic sensor manufacturers already have communications systems which might be built upon or the proposer may develop their own.
Preferred strengths for the project team include experience with inductive loop signatures, vehicle classification, vehicle identification, communications of traffic data, system integration, traffic engineering, and experience on sensor applications, software development and system communications. Also preferred are experience with traffic data collection and analysis for systems validation. Inductive loop sensor manufacturing capability or partnership with an inductive loop sensor manufacturer would be preferred. Understanding of Bluetooth data collection systems and how they might work with or complement Inductive Loop Signature systems is needed.
Relationship to FHWA Strategic Objectives ( from : FHWA STRATEGIC PLAN Publication No. FHWA-PL-08-027, October 2008, http://www.fhwa.dot.gov/policy/fhplan.html)
System Performance - Objective 1 - Performance Indicators - Develop and use a nationally recognized, credible, balanced, and readily digestible suite of national highway system performance indicators, focusing on the NHS, Strategic Highway Network, and other major arterials and intermodal connectors. (Strategic Plan Page 11)
Note: The outcome of this study will be a robust system for collecting, analyzing, and integrating and communicating system performance.
Objective 2 - Performance Improvements: Make significant improvements to critical aspects of highway system performance (safety, congestion, reliability, infrastructure condition, air quality, user satisfaction, and emergency response). (Page 12 of Strategic Plan)
Note: Only Bluetooth and loop signature identification/re-identification systems have the current potential to evaluate causes of congestion. System performance measurement at a reasonable price point for deployment is a critical key to assist in creating solution strategies. oSuch systems would enable metropolitan areas with comprehensive, network level traffic signal management systems to monitor and maintain system performance. These systems would also allow urban and rural jurisdictions to provide access to real-time travel conditions information, such as 511 travel information systems and dynamic message signs where loop based systems currently exist.
These outcomes cannot be reached unless systems can reliably and accurately detect and characterize vehicle segment traffic travel times and road segment to road segment origin-destination movements in all weather and lighting conditions. Inductive loop signature technologies are fully all weather and software would allow them to emulate probe vehicle data with 100% sampling. The desired outcome of this study is hardware and software which will enable implementing these strategies.
Relationship to fuel consumption and emissions - Improved highway system performance in safety, congestion, and reliability, directly caused reductions in fuel consumption, CO2 emissions and air quality for the same VMT.
Note: Providing real time travel time measurements and origin destination data to traffic control systems would allow construction of new kinds of algorithms for Adaptive Control Systems (ACS) and Traffic Responsive Control Systems that cannot exist with current technology.
Problem Statement
Effective signal timing is a process that requires system-wide data collection and analysis, expertise with conventional timing theory, and localized signalization experience for best outcome.
Project Goal and Objectives
The goal of this project is to develop a comprehensive signal analysis tool, which has the capability to collect system-wide traffic data and localized expert knowledge, and to perform system-wide signal timing analysis for the diagnosis of any signal timing problem.
Objective #1
To develop a low-cost, wireless networked sensor group which can be easily deployed for temporary data collection. The data from sensors will be transmitted to a central computer through the wireless network.
Objective #2
To develop a data interface tool that can perform data fusion and data pre-processing for the analysis tool.
Objective #3
To develop a knowledge-based Expert System that can use conventional traffic signal timing theory, localized knowledge on signal networks and timing plans to perform signal system analysis.
These objectives are often not met in real world practice due to certain technical constraints and the optimal system-wide time is not achieved.
Major constraints include:
BACKGROUND
Here is an example of signal constraint:
As shown in Figure 1, a major corridor runs E-W direction and needs guaranteed green time to maintain progression. There is a frequent delay at intersection #3 on this major corridor. But the reason for that delay is not initially clear - why is there such a long delay at Intersection #3?
Through a system-wide analysis it was found that the cause of this delay was due to the timing at intersection #1 - at this intersection a frequent, preferential service was given to the minor street, meaning vehicles at the minor street did not have to wait a long time to get green light. In this way, platoons of vehicles on a major corridor were stopped frequently causing wasted green light time at downstream intersection #2. In order to enhance progression, intersection #2 had to increase its green phase to compensate for the lost green time. Unfortunately, this increase caused delays on Oak Street (see diagram below). Consequently, traffic queues on Oak Street would frequently extend into intersection #3 and then block Main Street traffic. This was the main reason for traffic delays on Main Street at the intersection #3.
This example shows that in order to figure out the problem in one intersection, system-wide, synchronized traffic and timing data is required, as well as conventional timing theory and localized knowledge. If a system-wide approach is not employed, unanticipated consequences may occur at other locations.
Figure 1 
The Benefits of the Project
Every day, traffic delays and air pollution are caused by ineffective traffic signal timing. However, it is very hard for traffic agencies to expedite timing solutions due to lack of resources and effective tools.
The Intelligent Signal Analysis Tool, which will be developed in this project, will be a powerful tool to help the agencies address signal timing issues. This tool will provide effective diagnosis of timing problems and serve as a powerful evaluation tool. Using the tool, traffic agencies can save costs in data collection and achieve much better signal timing.
In summary, this tool will greatly improve signal timing-traffic delay and air pollution will be greatly reduced.
Phase I Tasks
Task I
To develop and test 20 low cost sensors (such as magnet sensors) in a network with wireless networking capability. Sensor data needs to be time stamped and transmitted to a central computer.
Task II
To develop and test a data interface which can receive data from sensors and controllers through a wireless network. This interface also performs data fusion and pre-processing for the knowledge base.
Task III
To develop a prototype knowledge based Expert System. The Expert System will be powered by rule-based knowledge from human experts. It will produce output using the knowledge base and pre-processed data, and it will also have capability to interact with human experts as well as simulation programs.
Task IV
1) To apply the developed sensors group to a small traffic network to demonstrate the data collection functions, 2) To input the collected data and collected localized expert knowledge into the data interface, and 3) To demo the data fusion and pre-processing functions.
Task V
To apply the Expert System with a simulated signal system using collected traffic and signal data. The task is to demonstrate the capability of the expert system.
The deliverable of Phase I is a functional prototype signal analysis tool.
The Phase II Expectations
After the proof-of-concept in Phase I, following steps are expected in Phase II:
OBJECTIVE
Use object-oriented structured programming and JAVA (a programming language developed by Sun Microsystems) to enable open source TEXAS (Texas Experimental and Analytic Simulation) intersection collision simulation to model Signal Phase and Timing data (SPAT) broadcasts and Geometric Intersection Description (GID) broadcasts to vehicles.
TECHNICAL DESCRIPTION
The TEXAS model is a high-quality single intersection simulation model. TEXAS analyzes in microscopic detail the behavior of vehicles as they go through intersections and mix with other traffic flows. Most simulation models discard this level of detail in favor of focusing on the surface street network for congestion mitigation or planning purposes. TEXAS has path following, microscopic car following, visibility restriction features and surrogate safety measures allowing it to be used for intersection collision analysis. This makes it suitable for research into SPAT and GID modeling to facilitate research and design in the applications of these Intellidrive tools. Making SPAT and GID easy to model would encourage their use in the safety and operations design of intersections for Intellidrive that consider both traffic collision/safety potential and traffic operations enhancements.
The SPAT broadcast message consists of current state of signal phasing and time remaining in that phase. Under the broad category of DSRC, the Society of Automotive Engineers (SAE) is developing standards for SPAT messages. These draft standards are contained in SAE J2735. GID information is needed to accurately place the vehicle in the proper position within the intersection. The vehicle will have latitude and longitudinal information of its location through GPS. Intersection information is needed to place the vehicle in its lane as well as determine vehicle position relative to the stop line.
For the purposes of this study, it is envisioned that SPAT and GID will consist of a separate set of routines that have access to the signal state and timing of the controller. It will then "broadcast" by simulated messages over the "DSRC" to vehicles. A simulated vehicle on board application can then perform a number of functions consisting of an advisory to the simulated driver, partial vehicle control, or full vehicle control to prevent simulated crashes.
PROJECT ISSUES
This project will also use object-oriented structured programming techniques and JAVA to adapt the open source interactive graphical interface of the TEXAS intersection collision simulation for intersections (stop sign, pre-timed and actuated traffic signals) to handle SPAT, GID and Intellidrive applications. (Note- this interface is and would have to remain "Section 508 handicapped accessibility" compatible). TEXAS and its interface program and all of its code are copyrighted under the Free Software Foundation statement. The SPAT/GID enabled model would continue to be programmed in JAVA and Fortran 2000+ to continue their platform independence. It would continue to run on at least Windows XP, LINUX and MacOS and if possible, Windows 7.
PHASE I AND PHASE II DELIVERABLES
Phase I would develop a simple SPAT and simulate a simple Intellidrive application using the SPAT data.
Phase II would add configurable SPAT and GID features and additional Intellidrive applications such as those being worked on by UC Berkeley, Va Tech and the University of Minnesota, and Bonneson's red light running reduction system.
Phase II would also enable running of vendor PC-based emulators of real traffic signal controllers as well as SPAT enhanced hardware in loop simulation. Phase II will be staged with interim deliverables. For this reason, experience in traffic simulation modeling, JAVA, section 508 compatible data entry, CAD and traffic operations are critical.
Note: Although not required, it would be helpful if you provide in your proposal a working example to demonstrate your ability to work with Java and user interfaces.
For an overview of TSIS, CORISM and related materials see: http://ops.fhwa.dot.gov/trafficanalysistools/corsim.htm
The following site explains the philosophy of the GPL. http://www.gnu.org/philosophy/free-sw.html
This site explains categories of software, copyright and the description of the license: http://www.gnu.org/copyleft/gpl.html
Relationship to FHWA Strategic Objectives (from: FHWA STRATEGIC PLAN Publication No. FHWA-PL-08-027, October 2008, http://www.fhwa.dot.gov/policy/fhplan.html)
The flange way gap at grade crossings present a hazard to people in wheelchairs and on bicycles. The narrow tires of wheelchairs and bicycles can get trapped in the flangeway gap and either trapping the person or throw the person from the wheelchair or bicycle. The purpose of this Phase I study is to develop a variety of materials or devices which will fill the gap under light loads of a wheelchair or bicycle but compress or retract when a train wheel flange passes over it. The material or device will be tested under heavy and light train loads for safety, effectiveness, durability, and cost.
The purpose of this research is to develop a low cost system to determine when a person or vehicle is in the grade crossing. The life cycle cost of the system must be less expensive than loop detectors. The system will be tested and compared to loop detectors in terms of installation, maintenance and operation costs, as well as safety, effectiveness, and reliability.
The purpose of this research is to develop and test a constant warning time grade crossing activation system which minimizes the use of track detectors and circuits through the use of Differential Global Positioning System (DGPS) and telecommunications. The system must be fail safe and be very reliable. The system will be tested and compared with current track circuit technology. The objective is to develop a system that performs better than current technology, is as safe or safer, and costs less.
It is necessary to increase employee safety during yard inspections and operations. The purpose of this research is to design, develop and test an advanced inspection vehicle which will not only enhance operation efficiency but most importantly, improve employee safety in rail yards. The system must have the ability to perform complex tasks and access small yet dangerous spaces in order to perform complete and comprehensive inspections procedures. This modular vehicle concept is intended to provide either remote operation or autonomous navigation in the rail yard. The advanced inspection vehicle will perform automated car inspections and have the ability to conduct various maintenance activities.
FRA wishes to investigate the possibility of designing a portable Field Welding system that can improve the reliability and safety of railroad infrastructure. Failure of in field welds are a significant cause of rail separation that leads to track caused derailments. Through the testing and development of improved Continuous Welded Rail (CWR) field welding techniques, both track maintenance time and track derailments can be reduced. The system should generate welds that meet or exceed AREMA specifications and substantially reduce the current down time associated with field repair of CWR sections (allowing for minimal track/service interruption) and reduce costs associated with existing welding technologies (i.e., thermite & flash-butt) by use of the portable innovative welding system. The system should be of a scale that allows for ease of transportation to and from multiple track locations and be self contained allowing for repeat usage as needed
FRA wishes to investigate the possibility of designing a non-contact track gage measurement device. This system should be easily installed on any rail vehicle (locomotive, passenger or freight cars) and measure the track gage in accordance to FRA track safety standards. In addition the system should be able to operate in adverse weather conditions (rain, snow) and should not interfere with track components or vehicle operation. The system should be able to collect all the data in both the forward and the reverse move at all speeds up to 125 mph and report the data at one foot interval. The measurement range and accuracy for each channel are as follows: (Gage (inches): 55 1/2" to 58 1/2" Range, 0.0625" Precision). The current technologies (contact, optical, or eddy current) will not be considered.
Economical and durable technologies and devices for improving safety for riders and transit agency employees, reducing noise and energy consumption, or improving the rider experience. The innovations must be adaptable to existing bus and rail transit vehicles and systems.
Human factors play a large role in crash causation. The extent to which human factors play a role has been quantified by the Large Truck Crash Causation Study, published by the FMCSA in 2006, where driver behavior was associated with 87% of the 141,000 truck crashes (fatal and injury) covered by the study. The vehicle itself was associated with 10% and the environment with just 3% of the crashes in the study. It is considered that the conclusions reached in the Large Truck Crash Causation Study above are similarly valid for passenger cars and light trucks. In order to manage driver behavior more effectively, it is necessary to measure this variable directly, and ideally, in near real time.
For this technology to have maximum impact, it must be available for the existing national fleet, be generally independent of vehicle systems (except for power) and be relatively inexpensive, so that the adoption rate will be meaningful, and thus have a measurable effect on the national crash rate.
Although a number of after-market systems that monitor drivers exist (e.g., camera base technology), they do not integrate real-time data analysis and transmission of driver behavior to the driver and fleet operator. Such a system would provide both the driver and the fleet operator significant information. The driver could modify undesirable behavior and the fleet operator could determine driver's performance and have objective information of incidents that may occur in near real time.
Phase I will address five activities:
The outcome of Phase I will be a demonstration of a system for driver behavior and crash avoidance monitoring, incorporating the elements described above. The demonstration should be an advanced concept or prototype. A final report and presentation will be required also. It should include clear description of concepts for feedback that do not cause undue distraction to the driver.
A Phase II would be an effort to further develop, refine, and test the concept or demonstration of the Driver Behavior and Crash Avoidance System. Methods for manufacturing and commercialization of the product would be identified in Phase 2.
In 2007, according to the National Highway Traffic Safety Administration's (NHTSA) National Center for Statistics and Analysis, 36% of all motorcycle riders involved in fatal crashes were speeding4 compared to 24% for passenger car drivers, 19% for light-truck drivers, and 8% for large-truck drivers. There are increasing reports in multiple State jurisdictions across the United States that motorcycle riders intentionally conceal motorcycle license plates and operate their vehicles in a reckless manner on public roadways knowing that (1) law enforcement personnel do not possess a tool with which to positively identify the motorcycle or the rider, and (2) law enforcement personnel are prohibited from engaging in high-speed pursuit in many jurisdictions. Therefore, the goal of this research study is to develop a radio frequency identification (RFID) system for motor vehicle (including motorcycle, passenger car, light-truck, etc.) license plates to assist law enforcement in highway safety activities. While the initial concept for this project is focused on improving motorcycle operator compliance with laws through increased technology for law enforcement agencies, there are other applicable roles for this technology (i.e., identification of stolen vehicles, etc.) that would benefit law enforcement agencies.
4NHTSA considers a crash to be speeding related if the driver or motorcycle rider was charged with a speeding-related offense or if an officer indicated that racing, driving too fast for conditions, or exceeding the posted speed limit was a contributing factor in the crash.
There is no one definitive "RFID technology". Rather, there is a wide range of technical solutions ranging from simple, inexpensive, and common to those with more functionality, performance, and cost. In its simplest form in common use today, an RFID system consists of four elements: a tag, antenna, reader, and host computer.
Phase I will address five activities: (1) conduct a literature review on existing RFID systems applicable to motor vehicles, toll collection, border crossings, and traffic flow monitoring; (2) develop the proof of concept for a RFID licensing system that law enforcement can utilize to accurately identify all motor vehicles within a 30' or greater radius of the RFID reader in a police cruiser and identify the direction/location of the RFID tag with respect to the location of the RFID reader in the police cruiser; (3) develop a mock-up of an RFID reader that would minimally impact a police cruiser's power supply, minimally impact available space in the passenger compartment and/or the exterior of the vehicle if equipment installation is required, and connect to existing law enforcement computer systems currently in use; (4) develop a mock-up for passive, read-only and read/write RFID tag/antenna that can be imbedded in (not affixed to) a motor vehicle license plate and can be programmed at the time of license plate manufacture or by a State agency at a later date with appropriate data, such as State name, license plate number, vehicle identification number (VIN), vehicle make, vehicle model, and vehicle model year; and (5) conduct a cost and methodology analysis for fully developing and field testing a prototype RFID licensing system developed under Phase I. The outcome of Phase I will be a final report on the proof of concept for a prototype RFID system for motor vehicle license plates, including a discussion on the technical aspects of the prototype RFID system, software packages, RF spectrum, accuracy and fall-off range, interference, tampering, cost, and methodology for conducting a field test or demonstration project.
If a prototype RFID licensing system for motor vehicles can be developed at a reasonable cost, the project would move to Phase II. Phase II would be an effort to fully develop, refine, and test the prototype RFID licensing system to include a small-scale field test or demonstration project. The objectives of Phase II are to (1) develop and refine the prototype RFID licensing system; (2) test the methodology and accuracy for storing, collecting, analyzing, and managing relevant data; (3) conduct a field test or demonstration project to test real world applicability of the prototype RFID licensing system. The outcomes of Phase II are to determine (1) if the prototype RFID licensing system is feasible; (2) the extent to which data can be stored, collected, analyzed, and managed; and (3) the extent to which jurisdictional law enforcement agencies volunteer to accept a new technology to enforce traffic laws. These outcomes would be included in a final report detailing the extent to which a full-scale study is feasible, and if feasible, describe the most efficient methodology for a full-scale study within a State jurisdiction.
Metallic lined composite cylinders have been used for many years under PHMSA's Special Permit Program. PHMSA has recently approved special permits for a composite cylinder with a non-load sharing liner. The failure modes of composite cylinders with non-load sharing liners are not well understood. DOT limits the life of composite cylinders to 15 years from the date of manufacture based upon work done by NASA and a desire to keep the possible failure rate below 1 in a million. There is a lack of information which can be used to predict the life expectancy of a composite cylinder in service. Research is needed into the development of a practical non destructive examination (NDE) method for conducting in-service testing of composite cylinders. The NDE method shall be capable of distinguishing the differences between normal fiber breakage and a critical crack which may cause cylinder failure prior to next requalification period (five years).