The County Feat

Rural region useshigh-speed digital imagingto meet GASB 34 deadline

Software Article August 16, 2003
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Last year a growing, rural county in the heart of Texas—located between Dallas and Austin—met its looming GASB 34 financial accounting deadline by using an automated van that records digital images of its pavements at high speeds.

The van, employed by Bell County, Texas, collects high-resolution digital images of pavement surfaces, at highway speeds of up to 70 mph, while simultaneously analyzing the images for pavement distresses.

The resulting database of pavements and conditions—indexed geographically using GPS—then was “rolled over” into Bell County’s pavement management system, which was used to assign a value to the county’s highway system, essential for adherence to new GASB 34 financial reporting guidelines for governments.

Bell County used the ADVantage (Automated Distress Vehicle) system of consultants Fugro Consultants LP (Fugro), the industry’s first completely automated digital pavement distress surveying system.

And while the county used a high-tech solution, its expenditures were substantially less than any other method for obtaining the pavement condition inventory, including hiring temporary help such as college engineering students, said Richard Macchi, P.E., Bell County engineer.
“We talked about hiring students, but we really didn’t have the expertise to train them on what should be done in performing a condition assessment,” Macchi said. “And we were afraid that the more eyes we would have out there looking at pavements, the more inconsistencies we would have. We really wanted something that was consistent and verifiable, and the ADVantage information was just that.”

The county did get estimates from other engineering firms, including manual inspection of the roadways, and the cost would have been significantly higher, Macchi said. “Another firm would have done vehicular assessment, and they also were higher,” he said. “Fugro turned out to be the most economical way of getting the job done.”

And it didn’t take all that long, either. “From the time they got out on the road to the time they handed us the initial results of the survey they took 30 days,” Macchi said. “That’s very reasonable.” This significantly contributed to the county’s meeting its GASB 34 reporting deadline of April 30, 2004.

Taking advantage

While the economics were important, the speed of getting a complete pavement condition inventory by the deadline drove Bell County’s selection of the high-tech option.

“We had never done a pavement inventory in Bell County,” Macchi said. “I had seen a demonstration of this vehicle’s technology so I knew what it was capable of. When the county auditor looked into the GASB 34 requirements—which included an accurate assessment of the value of the road system—I immediately thought of the ADVantage system.”

GASB 34 is bringing the accounting standards of the business world to that of government, and its pavement management attribute overlaps with the growing philosophy of asset management being promoted by the Federal Highway Administration’s Office of Asset Management (OAM). To the FHWA, asset management at the local government level is based on pavement management.

While compliance with GASB 34 is optional, it will be very difficult for governments to sell securities such as government bonds if they don’t adhere to the new GASB 34 standards.

“Failure to meet GASB standards would have made issuing of bonds much more difficult and probably much more costly,” Macchi said.
GASB (pronounced GAZ-BEE), the Governmental Accounting Standards Board, is a nonprofit organization whose standards provide accepted accounting procedures for all state and local governments in the U.S.

GASB Statement No. 34, Basic Financial Statements and Management’s Discussion and Analysis for State and Local Governments, was approved in June 1999. GASB 34 requires that state and local governments include long-lived assets, including roads and bridges, in their annual financial statements (see related sidebar).

GASB 34 is being implemented in three phases.

  • Governments with total annual revenues of $100 million or more were to apply Statement 34 beginning with fiscal years ending after June 15, 2002;
  • Governments with total annual revenues of $10 million or more, but less than $100 million, will apply Statement 34 beginning with fiscal years ending after June 15, 2003; and
  • Governments with total annual revenues below $10 million will apply Statement 34 beginning with fiscal years ending after June 15, 2004.

Bell County fell into the second phase, Macchi said.

Alone at night

Bell County’s pavement condition survey began with a county road map, which was all that was needed. “They needed a map showing where all paved roads were, with a listing by name and approximate, verifiable roadway width,” Macchi said. “They pretty much took it from there. We had minimal staff to go out to work with them, and they worked totally alone, and totally at night. If they had any questions, they’d come in the next morning and go back out to the location that night.”

Bell County’s contract was for the pavement condition assessment and for the contractor to take those data, with GPS data, and “segmentalize” all paved roads in the county. Now all paved roads are divided into half-mile segments, Macchi said.

Bridge values were obtained from Texas Department of Transportation inspections, which are conducted every two years.

Until an automated system of the type used by Bell County became available, government agencies had two options for pavement inventory surveys.
A straight “manual” method would require lane closures, with agency personnel or hired help—such as engineering students on summer break—visually rating pavement conditions and recording them on a large-scale road map. This method was slow, inherently dangerous, and the reliability of observed data may be suspect.

Second, a “semi-automated process” over the past two decades has used a vehicle-mounted, downward-oriented video camera to collect pavement condition video images at a faster rate of speed, generally 30-50 mph. After the data is collected, the film is played back for operators, who rate the pavement condition while viewing the video. While safer and not prone to repeatability problems, this option requires staff to travel the roadway twice, first in the vehicle and second at the office.

Image building

The system used in Bell County—Fugro’s ADVantage system—brings together imaging and computer analysis of those images to construct a reliable database of pavement conditions, with substantial savings in time and labor costs.

The digital image capture system, data storage system and data analysis system are all housed in a customized van, which is operated at night, or in low light, with four strobe lights to guarantee optimal illumination for capturing high-resolution (1296 x 1024 pixel) digital images of the roadway, Martin said.

The images are fed into an on-board computer system where they are stored and sequentially analyzed in real-time to identify the quantity and severity of cracks. Crack severity statistics are stored in a separate database.

The data are analyzed for longitudinal, transverse, block and alligator cracking patterns, and is geographically referenced with universal GPS/GIS coding.

A single high-resolution camera is mounted over the roadway from the rear of the van. The camera acquires up to 12 frames of digital images of the roadway per second. A digital image of the entire lane, 14 ft in width, is captured from the back of the van, with sequential longitudinal images stitched together by the processing software.

These images are analyzed to identify cracks and cracking patterns using optical character recognition based on pixel variations within the digital photos. This system automatically distinguishes between manufactured joints in concrete rigid pavement sections, and joints at bridge approaches, versus pavement distress. Also, an optional laser rut bar is provided on the ADV to capture pavement roughness and ride data.

Pavement distresses are identified, categorized and summed per the rules of the owning agency, and then these data can be “rolled over” into the agency’s existing pavement management system (PMS) database.

While not used by Bell County, in addition to pavement surface distress, a right-of-way digital image option is available, which allows viewing of roadway right-of-way simultaneously with pavement images, permitting logging of signposts, light standards, hydrants, sewer inlets and other roadway appurtenances.

Knowing the value

Bell County has approximately 1,300 paved lane miles in its system, with approximately 250,000 residents, Macchi said. The county’s existing geographic information system, CarteGraph Systems Inc., contains a pavement management module, but the county still is feeling its way through the merger of the pavement condition data into the PM module.

After the inventory, for the GASB 34 requirements, Bell County determined the value of its roads using new subdivision development-constructed streets as a base.

“We analyzed several developer contracts for new roads in subdivisions around the county,” Macchi said. “We came up with a current value per mile of roads by applying that number [100] to our current paved road inventory, then used the condition assessment [on a scale of 1-100] to establish the value.”

For example, if a road had a condition assessment of 85%, then it was considered to be 85% of what the new road would cost. The result was a finding that the average condition of Bell County’s system was 87.5%, with a historical value of $137.3 million, accrued depreciation of $31 million and a net book value of $106.3 million.

The condition assessment was used to determine an average start date for the roads, which was used to begin depreciation calculations.
Macchi said the program definitely was worth its cost, and hopes to utilize the ADVantage system in the future.

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