U.S. Department of Transportation
Federal Highway Administration
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At the time of this report, we found no transportation agencies having full-scale ISPE programs in place, although several pilot programs are underway. However, some transportation agencies do track specific roadway safety hardware or use asset management systems for roadway inventories that include roadside safety hardware. A few transportation agencies have also experimented with the investigated ID methods for a variety of purposes.
This chapter provides two examples of roadway safety hardware tracking and several examples of the investigated ID methods using tag identifiers; the latter includes examples from other industries to show the potential range of opportunities and limitations.
In an effort to better understand how some transportation agencies currently identify and document roadside safety assets, this report includes a review of two current asset management practices from the literature: Idaho and Florida.
The Idaho Transportation Department has a video-logging system, called GRail, to identify guardrails on the National Highway System. The agency developed the GRail application system using Microsoft® Access Visual Basic.
A vehicle equipped with video-logging equipment, GPS, and the ability to log distance traveled collects data along a roadway at highway speeds and takes images of the roadside hardware. During processing, users compare the photo log to existing records and then update those existing records if needed. Agency staff also enter new guardrail installation information manually from project plans.(7)
In 2012, the Lehman Center for Transportation Research at Florida International University investigated the in-service performance of strong-post w-beam guardrail and cable median barrier systems.(8) The result was a Web-based system called the Florida Guardrail System.
The Florida Guardrail System's database includes the county and road where the guardrail is located, the begin/end milepost, the position of the guardrail, the guardrail characteristics and condition, any guardrail damage, and the guardrail component repair records. The database allows users to look at information for guardrail systems on all Florida State roadways. Staff members populate the database manually from field records. The database allows the Florida Department of Transportation to maintain and correct inventory records in a timely manner.
Three primary ID methods could aid transportation agencies' ISPE or asset management efforts:
All three methods could be deployed through permanently attaching tags to hardware. Alternatively, barcodes and serial numbers could be printed on hardware, and serial numbers could be physically stamped into the material of the hardware. Typically, printing and stamping are completed during manufacture. Post-manufacture, transportation agencies and other industries are using physical tag identifier technology as an ID method.
The following examples illustrate the potential of post-manufacture tag identifiers (barcodes, RFID, and serial numbers).
Construction Materials
The Georgia Department of Transportation (GDOT) explored the use of RFID tags for tracking construction materials that the GDOT Office of Materials and Research tests. The Office of Materials and Research tests as many as 30,000 samples of construction materials and keeps track of its inventory through a paper-based system.
The investigation used read-only, passive, ultra-high-frequency (UHF) tags, which were linked to GDOT's Materials Information Management System (MIMS). Once the RFID tag was linked to the MIMS, the system tracked the time of arrival at the laboratory, assignment for testing, delivery to the laboratory for testing, completion of testing, entry of test results into the MIMS, and submission for review and approval of testing. Both a handheld reader and a fixed reader were used for tagging and ID.
The project established the durability of the tags through testing by placing the tags under high-moisture conditions; immersing the tags in water, acid, and base solutions; placing the tags in a freezer for at least 24 hours; and placing the tags on top of a concrete cylinder during a compression test. Overall, the tags proved to be very durable under all conditions and provided consistent readings throughout the test. Research findings showed that RFID tags are a viable option for material tracking.
The tags were relatively cost efficient. The cost of each tag ranged from $0.20 for one-time-use tags to $2.75 for reusable tags. The RFID reading equipment had some issues reading the least-expensive tags and was sensitive to tag orientation and attachment to metal. The distance for readability ranged from 10 to 13 ft.(9)
Signs
In addition, GDOT explored the use of barcode labels for newly installed signs.(10) Implementation has been delayed due to problems with database integration and some hardware issues, but it is still being pursued. The proposed labels are to contain all the information describing the sign. The database will include the following data fields: height, width, size, fabrication date, warranty date, cost, substrate material, sheeting manufacturer, legend and background sheeting types, legend and background colors, sign location, GPS coordinates, sign designations, side of the road and lateral offset, and installation date.
The Alaska Department of Transportation and Public Facilities and FHWA investigated the feasibility of using RFID technology in their work with the construction industry.(11) The investigation included a field evaluation of tracking price-pay items such as asphalt, base course, borrow, and riprap using RFID tags.
The existing tracking process required a computer-generated ticket that the truck driver carried to the dump point, where staff collected and processed the ticket information to create an accounts-payable item (payment) to the carrier or driver. To investigate the feasibility of using an automated tracking system, researchers installed 10 RFID tags on 10 different dump trucks. Tags were placed at the rear of each truck, and a tag reader was placed at the exit of the facility where materials were stored. The RFID tags kept track of the departure and return time of the trucks from the asphalt plant. Staff still manually entered the job identification number, the type of material being transported, and other information. Evaluation performance metrics for the RFID tags included accuracy, processing, and total time of each round trip by each truck. The RFID tags proved successful in tracking the dump trucks. There was a 16 percent error in data entry, but these were human errors in recording truck ID numbers and load type.
The Arizona Department of Transportation conducted a pilot implementation of a barcode inventory system for fixed assets.(12) In this investigation, a fixed asset was defined as an asset that is moveable, durable, and considered a capital asset, such as maintenance vehicles. The user can print a label using a computer and barcode printer, or can obtain preprinted labels. Barcodes can also have an embedded RFID tag.
The project had three implementation pilot strategies:
The total implementation cost ranged from $11,155 to $12,425. The cost included software licenses, staff training, 20,000 barcode labels, 2-year software and hardware support, and two scanner units. The pilot estimated a reduction of 26 percent in man hours needed to collect asset data when compared to manual techniques. The primary benefits of the barcode system were portability, on-site data entry capability, accuracy, and better reporting.
In June 2008, the Alabama Department of Transportation issued a specification for highway signing and maintenance.(13) The specification outlines a sign inventory system to keep track of installation, replacement, and/or repair of the traffic sign. The internet-based inventory includes the following data:
In the inventory system, the contractor delivers the data to the transportation agency through computerized download and the internet. Information about when a contractor replaces, installs, or repairs a sign is posted within 48 hours of the work. The barcode label must be 2.5 inches wide and 0.75 inches high, and have manufacturer specifications of a 12-year readable service life.
The Maryland State Highway Administration investigated the use of RFID tags and barcodes for inventory tracking. Specifically, the agency wanted to determine the abilities of both barcodes and RFID to track material field samples at the Office of Materials Technology's laboratories. The objective of the study was to recommend an ID method.
Maryland officials recommended the use of barcodes for all labs at the Office of Materials Technology. One reason for the recommendation was the use of barcodes in other construction applications and in the automotive industry. In addition, the Maryland study determined that laboratories with a large number of samples and a wide range of involved parties could benefit from RFID.(14)
Other industries have used tag identifier technology as ID methods, and transportation agencies may find opportunities to use the methods in innovative ways. The following examples show the breadth of the technology's use.
The Forest Service's Forest Inventory and Analysis Program conducted a national census to assess America's forests. At the time of the report, the program was using metal tags, which after several years are consumed by the trees or otherwise lost.
The Forest Service used passive UHF tags and tested two different kinds of readers. After an indoor test, the team selected 12 tags for outdoor testing. However, none of the 12 tags were readable from distances greater than 15 ft. in outdoor conditions. Researchers concluded that at a price of $0.45 per tag, the cost was too great for the Forest Service to purchase and use RFID tags. The research findings showed that if the cost of RFID technology continues to decline, RFID tags could be an attractive option for tree inventory.(15)
Ozguven and Ozbay introduced a comprehensive feedback-based emergency management framework to maintain a safe amount of vital supplies such as medicine, food, fuel, and power.(16) Researchers noted the need for such a tracking system and database in the aftermath of Hurricane Sandy.
The effort estimated that although RFID tags are more expensive than barcodes, they may be more reliable. In addition, RFID tags can track the movement of supplies and minimize data entry and collection errors because they reduce information-processing time.
Construction Materials
In 2006, Song et al. presented an automated tracking system for construction materials that would identify and track materials at construction sites without adding to regular site operations.(17) Researchers studied off-the-shelf RFID tags and tag readers, and set up a testing region in an open field.
The team read and located tags accurately within the region 93 percent of the time. The findings listed compatibility with construction environments as one of the advantages of RFID tags. Passive tags worked well for construction, and the process did not require line-of-sight tracking, thus making tracking faster.
Pavement
In 2014, FHWA investigated the application of RFID tags on pavement.(18) The research evaluated the tracking of the placement of hot-mix asphalt and Portland cement concrete truckloads, pavement temperature and depth, and early detection of cracking in overlays. Two tags were encapsulated in a chlorinated polyvinyl chloride pipe and placed within the pavement:
Surface acoustic wave RFID tags have longer read ranges and can measure temperature. Researchers placed the tags in the new pavement construction of three parking lots. For hot-mix asphalt, the field test resulted in a 60 to 80 percent read success after construction. For Portland cement concrete, however, none of the tags could be read 1 month after construction. The research findings concluded that RFID tags were an appropriate application for hot-mix asphalt applications but not Portland cement concrete applications.
The Southwest Jiaotong University in China investigated the application of RFID tags as a replacement for barcodes and their impacts on logistics.(19) The effort estimated that the warehouse and retail logistics industry can use RFID in transportation and distribution management, storage and warehouse management, and circulation processing management. The reasons for improvement in logistics are that RFID tags avoid human intervention and accelerate delivery, the tag is non-contact, and the industry can use the tags in lean production. Benefits also include increased productivity by reducing human error, achieving a dynamic supply chain data in real time, improved delivery logistics through control of transportation, and reduced data entry that improves information accuracy.
Freight Cargo
Transcore uses hardened outdoor RFID tags placed on individual railcars for tracking purposes. By using a static reader, Transcore can automatically collect data about the railcar's destination and inventory.
Electronic Utility Tracking and Verification
The Texas A&M Transportation Institute and Prairie View A&M University studied the feasibility of using RFID tags to manage utilities, outdoor advertising, and other highway infrastructure within the Texas Department of Transportation right-of-way.(20)
The project found the following advantages of using RFID tags:
Some disadvantages of RFID include improper placement of the tag, which may corrupt readings; cost; and security and privacy issues.
Active tags were able to perform on all tests: use for underground facilities, metallic and non-metallic pipes, different soil types, the distance of the reader from the ground, passive and active tags, and the readability of tags for overhead structures. For passive tags, as the distances below ground increased, readability decreased. The research findings showed that RFID technology is not adequate for widespread use for asset management because of the numerous assets that are present on the roadway, and the application of RFID tags would require a significant financial commitment. However, RFID tags showed promise for limited applications.(20)
The transportation field and other industries have successfully used barcode, RFID, and serial number tag identifiers as an ID method. However, examples of use for safety hardware are very limited, and no full-scale ISPE programs were identified. These findings rely heavily on manufacturer information to further detail the capabilities of tag identifiers as an ID method.
The next chapter gives an overview of technologies that are used to tag roadway safety hardware, termed tag identifiers.
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