Hottest Trends for the New Year

Road Science

Hottest Trends for the New Year

Here’s a quick rundown on some of 2004’s cutting-edge themes in transportation infrastructure construction, maintenance.

by Tom Kuennen, Contributing Editor

Concrete is paved over asphalt. Shovels are out, GPR is in. Drowsy drivers are out, rumble strips are in.

These are a few of the white-hot trends we’ve been following that have gotten bigger in 2003 and are on the cutting-edge of transportation infrastructure construction and maintenance for 2004 and beyond. Join us in an end-of-year, round-robin look at some of the hot topics that will influence your job and career in the months ahead.

Hot Topic No. 1

High-performance concrete moves from bridges to roads. HPC is migrating from demonstration projects involving bridges, to high-level pavements in the field.

HPC is a set of specialized concrete mixes which provide added durability for concrete structures. These provide ease of placement and consolidation without affecting strength, long-term mechanical properties, early high strength, longer life in severe environments, while using less material, potentially fewer beams, with reduced maintenance, extended life cycle and if designed well, enhanced aesthetics.


Concrete is paved over asphalt interlayer on Michigan I-75	HPC concrete overlay contains 25% ground granulated blast furnace slag as cement replacement	The I-75 overlay demonstrated cost savings over rubblize and asphalt overlay.

HPC was a component of the Strategic Highway Research Program’s Concrete and Structures section. Under SHRP, four types of HPC were developed:

Very early strength (2,000 psi@6 hours).
High early strength (5,000 psi@24 hours).
Very high strength (10,000 psi@28 days).
Fiber-reinforced HES, with steel or poly fibers added to control shrinkage cracks.

Originally, HPC was targeted at bridges. Bridges and decks built with HPC in Georgia, Minnesota, North and South Carolina, Missouri, Iowa, Texas, and many more states attest to the growing acceptance of HPC. But now, HPC is moving into pavements and it’s part of a long-term trend.

One such pavement this year was a test section constructed by the Michigan Department of Transportation in conjunction with the Michigan Concrete Paving Association. The project is a 4-mile stretch of northbound I-75 in Ogemaw County constructed by John Carlo, Inc., and involved an overlay of the existing 30-year old PCC pavement with a 6-inch concrete overlay separated by a 1-inch layer of hot-mix asphalt, sandwiched between old and new concrete to eliminate any reflective cracking.

Standard Type I cement was used, with 25% replacement of cement with ground granulated blast furnace slag as a durability admixture.

“The goal of this demonstration is to explore options that could lower costs to the department for concrete overlays,” said Bob Risser, P.E., MCPA executive director. “So far, the cost question has already been answered. The total cost of the concrete overlay was only 6% more per square yard than the rubblize-and-asphalt project on the southbound side. If the innovations we are looking at perform as expected, the cost of this new design will be less in initial cost than the rubblize-and-asphalt overlay option, while still delivering almost twice the life.”

Flexural beams broke at over 600 psi in two days and over 800 psi in only five days. The high early strengths helped John Carlo meet the demands of having to have two lanes open each weekend for tourist traffic.

A recent landmark application of HPC was Revive Wacker Drive in Chicago, notably the enormous mass pour of enhanced HPC (1,161 cubic yards) in May 2001 for this viaduct reconstruction for the Chicago Department of Transportation. This mass pour was a 240-foot-long by 110-foot-wide deck slab at State St. and the Chicago River.

Most HPCs include cement plus substitution of blast furnace slag, silica fume, or fly ash. But this was a unique quaternary mix, with all four elements of cement, slag, Class F fly ash, and microsilica. The city was looking to attain the optimum mix for durability, and the proportions and composition of the mix complement one another to attain a 75- to 100-year life cycle on this project.

The HPC mix for Wacker Drive incorporated strength of 6,000 psi in 28 days, with 4,200 psi at post-tensioning in three to four days. The mix was designed to control shrinkage and thermal contraction to minimize cracking, and provide long-term resistance to attack from alkali-silica reactivity, alkali-aggregate reactivity, and delayed ettringite formation. After placement, the deck was covered with a latex-modified concrete driving course which serves as an impervious, sacrificial friction layer.

More information about HPC for bridges and pavements is available from http://knowledge.fhwa.dot. gov/cops/hpcx.nsf/home.

The search for more durable, high-performance concrete is leading to some strange developments. For example, researchers at the Department of Energy’s Los Alamos National Laboratory have discovered that enlarging the ends of small fibers — giving them a dog-bone shape — when mixed into concrete, substantially increases the material’s overall strength and toughness.

The researchers found that adding 1% bone-shaped fibers to concrete can increase its maximum strength up to 84%, and its toughness up to 93 times. The finding has solved a problem of getting effective load transfer between fibers and the surrounding matrix without making the composite more brittle, as happens when the fibers are tightly bonded to the matrix.

Hot Topic No. 2

Smart structures and the FHWA’s nanotechnology initiative. Information technology and embedded sensors are bringing a new era to structural and pavement inspection.

This future is described in a scenario in a recent paper, Issues in Delivering Mobile IT Systems to Field Users, by J. H. Garrett, Jr. and J. Sunkpho of the Department of Civil and Environmental Engineering, Carnegie Mellon University.

“Imagine that a team of bridge inspectors is inspecting a large highway bridge,” they write. “Some inspectors are visually inspecting the more accessible parts of the structure. They rapidly record what they are seeing using a speech interface to their data collection device.” Existing conditions can be immediately compared to that reported during previous inspections by viewing — on the handheld — any of the previous inspection reports stored in a central database.

“Some inspectors are querying sensor systems embedded in, or attached to, specific locations on the structure using a mobile device for interfacing with these various sensors,” they write. “The inspectors are able to access the loading conditions and corresponding structural responses, and any changes in local material properties, of the structure since the last inspection period.”

But that future is now. This year a Portland cement concrete maturity meter was imbedded in the pavement of Grand River Road in Oakland County, Michigan, by Tony Angelo Cement Construction Co. of Novi, Michigan, in conjunction with the city of Novi, consultant JCK, and the Michigan DOT.

PCC pavements must attain correct strength and maturity before opening to traffic. Conventionally this is done by collecting concrete cylinders or beams in the field and testing them in a lab after several days of curing. Maturity meters offer an alternative to the traditional concrete cylinder testing for strength.

Several wireless maturity meters, attached to rebar and about the size of a candy bar, were imbedded in the newly placed pavement. Using a handheld computer, data were collected and analyzed to provide a concrete strength value. Recorded data include current temperature of the pour, date and temperature when poured, and dates on which it was last checked.

Because the wireless meter provides immediate and continuous data, on the progress of the strength gain Michigan DOT was able to open the pavement without delays.

But this is just the beginning. Future wireless data sensors will be buried as aggregate in concrete and be able to track a number of parameters, and yield the information when scanned. Research is continuing on these so-called “smart aggregates”.

A 2002 Maryland State Highway Administration/Transportation Research Board project, Smart Aggregates for Monitoring Corrosion, Phase I, developed a prototype sensor suite (smart aggregate) to monitor the corrosion environment in steel-reinforced concrete. Its goal was to allow the state to routinely perform comprehensive assessments of bridge structural integrity, with minimal time and resources.

This year Phase II began, in which the Johns Hopkins University/Applied Physics Lab is developing and testing a prototype of a measurement system that would collect, process, and record data from individual smart aggregate sensors. This will culminate in a long-term field test in a Maryland bridge deck.

Ultimately, nanotechnology — the science that studies breaking down matter particles at the most minuscule scale of atoms and molecules, and changing their characteristics — will drive management of our nation’s highways and bridges, and it’s being spearheaded by the Federal Highway Administration’s Turner-Fairbank Highway Research Center.

The FHWA foresees a future in which cracked bridges and potholes repair on their own, guard rails realign automatically after impact, bridges adjust their shapes to control movement caused by winds, and metal structures self-clean to avoid corrosion are among the advances in highway technology forecast by scientists.

Nanotechnology may enable these multiple breakthroughs.

Through nanotechnology, properties of matter can be manipulated to achieve better results, for example, by changing molecules of asphalt and cement to optimize certain features and create pavements with much better performance.

Road sensor networks also could gather and provide data to transportation operators to manage congestion and incidents better and detect fast-changing weather conditions.

More information on this initiative is available from www.fhwa.dot.gov/pressroom/nanotech.htm.

Hot Topic No. 3

Composite bridges near prime-time. Construction of bridges from factory-made kits is a growing trend, saving time and money for the owning government agency. But a new twist is the use of plastics, fiberglass, and high-performance adhesives in creating the bridges of the future.

In August 2001, the National Composite Center signed an agreement with Martin Marietta Composites of Raleigh, North Carolina, for the fabrication of six new composite bridge decks under a new program called Composites FOR Infrastructure.

The initiative facilitates fiber-reinforced polymer bridge deck installations without state subsidies, as well as examining other infrastructure-related applications for use of composite materials.

The first composite bridge deck under this program was installed in April 2002 on Fairgrounds Road in Greene County, Ohio. With three spans totaling 7,074 square feet, the new deck marks the largest to be successfully installed under the C4I initiative to-date.

The National Composite Center was in the midst of installing five more bridges through 2003, and is working with other Ohio bridge owners to install additional decks. These projects have resulted in the establishment of two FRP deck suppliers in the Dayton area. For more information, visit www.compositecenter.org.

In addition, TRB’s National Cooperative Highway Research Program Report 503: Application of Fiber Reinforced Polymer Composites to the Highway Infrastructure includes a strategic plan for guiding the implementation of fiber-reinforced polymer composite materials into highways.

This strategic plan contains 11 important elements and is supplemented by white papers describing the state of the art of seven applications of FRP composite materials. You may download Report 503 at http://gulliver.trb.org/publications/nchrp/nchrp_rpt_503.pdf.

Hot Topic No. 4

GPS can track your fleet in real time. The trend of automated systems using global positioning system satellites to track fleet movements is saving time and money for users, while providing new data to both government agencies and the private sector.

For example, the city of El Paso, Texas is fine-tuning its street sweeping by using Sidekick fleet management systems on its Elgin Eagle sweepers. This GPS-based innovation records sweeper movements, brush use, and other activities for later analysis.

Using this system, El Paso is compiling an extraordinary database and already has been able to measure its amount of curbing to the sub-meter, which is incorporated into the city’s pavement inventory database.

Sidekick data recorders are provided by GPS Supply, Alexandria, Virginia, and use map data by Navtech (Navigation Technology) to record sweeper movements and equipment use for further study. The system does not operate in real time as a police tracking system would, but is being used to develop equipment use profiles that can improve performance.

And for a Florida concrete supplier, a fully integrated, next-generation mixer dispatch and automatic vehicle location system is providing increased customer satisfaction and enhanced fleet productivity.

At Tarmac’s Eastern Region, in West Palm Beach, this system brings together a concrete mixer dispatch system with a GPS, providing real-time location status with a wireless communications network and Internet connectivity.

Concrete mixer dispatch software from Systech Inc. is integrated with Telvisant fleet management system from Trimble, to provide automatic truck status and dispatch capabilities. Mixer truck “events” such as the start and stop of the loading process, departure from plant, arrival at job site, and start and end of pour, are automatically and accurately captured and “time stamped” in a database without any effort by either the driver or the dispatcher. And via truck-mounted sensors, the system also captures and logs mixer data such as the number of drum revolutions or amount of water added at job site.

The firm can take more orders because it’s improving its yards-per-driver hour. Under the old system, when a truck would re-enter the plant, it might have sat for 15 to 20 minutes, and dispatch not realize the truck was back. Now Tarmac knows the instant the truck is back in the plant and its status. And if a customer calls for same-day service, it gives the dispatchers a better tool to gauge whether Tarmac can provide it.

Truck-mounted sensors provide mix data, which are stored. If a customer is plagued with low cylinder breaks, Tarmac can know exactly how many gallons of water actually went into the load of concrete.

Hot Topic No. 5

Ground-penetrating radar sees the unseen. Ground-penetrating radar and electromagnetic detection will help roadbuilders reconstruct roads and streets painlessly by precisely locating buried active and abandoned utilities, and they are tools that will grow in acceptance, especially when in built-up urban areas where reconstruction is painfully disruptive.

“The nature of these widening projects forces contractors to work in congested areas where space is limited, utilities are abundant, and reduced construction durations are critical,” says Hope Roark, resident construction manager, Fluor Corp.

During road construction, storm drainage systems may be upgraded or re-routed and the relocation/upgrading of existing utilities may be included in the construction contract. “One-call” services will mark the underground utilities on the surface.

“However, this process is very imprecise and leaves much to chance,” Roark says. “Depths are not known, all affected utilities may or may not participate, marks are only accurate to plus or minus several feet, and some utilities are inadvertently left unmarked.”

Now, Fluor’s Subsurface Utility Engineering is a tool that many states are using to minimize the hassles of underground utilities in road construction. SUE is the process of surveying an area for underground utilities and providing information in three dimensions.

In its most advanced implementation, SUE involves electromagnetic surveys and non-destructive excavations, Roark reports. Electromagnetic surveying encompasses several different techniques. These techniques can be as simple as the use of metal detectors and trace wires or as complex as GPR or elastic wave methods.

Under TEA-21, the South Carolina DOT entered into a public-private partnership with Fluor to manage projects in the western portion of the state. South Carolina wished to fund 27 years’ worth of planned and/or designed projects in just seven years. But the inability of local utilities to work at that compressed level jeopardized the “27 in 7” program.

SC DOT is using the SUE system to help offset, whenever possible, the burden caused by the relocation of existing utilities to the utility companies. One such project was in Greenville — called the Western Corridor — which involved the widening of a four-lane road to seven lanes. After reviewing the utility “as-builts” in comparison to the roadway plans, a list of potential conflicts was created. A SUE firm was hired to use non-destructive test methods to provide detailed information about the utilities.

“We are closely monitoring those projects on which SUE services have been employed and we have already documented cost savings during the preliminary design phase,” says D. Kevin Ulmer, SC DOT subsurface utilities engineer. “However, the majority of cost savings will be realized in the way of lower construction bids, because of more detailed utility plans and fewer delays caused by unmarked or inadequately marked underground facilities.”

Hot Topic No. 6

Foamed asphalt stabilizes bases. Base recycling using foamed, or expanded, asphalt is getting a closer look by local, state, and even the federal governments.

Using equipment such as the CMI Corp. RS-650 pulverizer, the Caterpillar RM-350 reclaimer/mixer, or the Wirtgen WR 2500 S reclaimer, failed asphalt roads are being foam-asphalt recycled in one or two passes. The road stays open to traffic while it undergoes complete recycling and stabilization as base material prior to overlay.

With foamed asphalt stabilization, excessive weeks-long truck traffic, demolition material and virgin aggregate hauling, noise, dust, and commotion are eliminated, and a virtually new, high-performance road base is created at a fraction of the cost of new base materials and deep lifts of asphalt pavements.

Foamed asphalt — the product of the injection of a predetermined amount of cold water into hot penetration-grade asphalt in a series of individual expansion chambers — replaces costly asphalt emulsions in base stabilization.

The expanded asphalt has a resulting high surface area available for bonding with the aggregate, leading to a stable road base using 100% of the existing in-place materials. Unlike asphalt emulsions, foamed asphalt does not require a three- or four-day “break” period before it can be mixed. The foamed base then is graded and compacted, and can permit traffic — including heavy trucks — almost immediately.

“The foaming only lasts a few seconds, but it’s long enough for the bitumen to expand and coat the aggregates,” says Tom Jones, project engineer from the FHWA Eastern Federal Lands Highway office in Sterling, Virginia. “By coating the finer aggregates, it holds it all together.”

For an overview of the FHWA’s application of foamed asphalt in a national park setting, visit www.tfhrc.gov/focus/aug03/04.htm.

Hot Topic No. 7

Pavement preservation gets national nod. Pavement preservation is a planned system of treating pavements at the optimum time to maximize their useful life, enhancing pavement longevity at the lowest cost. Experience shows that spending a dollar on pavement preservation eliminates or delays spending $6 to $10 on rehabilitation or reconstruction costs.

For local road agencies, the advent of the asset management-based accounting guidelines under the GASB 34 guidelines now being applied to local governments will encourage pavement management and preservation in coming years.

Today’s pavement management systems will give street departments the data they need to justify additional maintenance spending and pavement preservation, and to support the requirements of the new GASB 34 guidelines.

In June 1999, GASB Statement No. 34: Basic Financial Statements and Management’s Discussion and Analysis for State and Local Governments was approved. GASB 34 requires that state and local governments include long-lived infrastructure assets, including roads and bridges, in their annual financial statements beginning as early as fiscal year 2002.

But pavement preservation in the GASB 34 era got a big boost when the ribbon was cut October 17 dedicating the new National Center for Pavement Preservation at Michigan State University.

The center — located in the MSU Engineering Research Facility — was founded earlier this year by MSU, the FHWA, and the Foundation for Pavement Preservation to lead and coordinate collaborative efforts among government, industry, and academia in pavement preservation.

The Foundation for Pavement Preservation and its public and private sector partners say the key to optimized pavement life is the application of the “right treatment, to the right pavement, at the right time”. Now, the NCPP will be able to advance and improve pavement preservation practices through education, research, and outreach.

“Pavement maintenance and preservation never have had a national focus, an organization that could champion and conduct needed research, nor a forum for developing and training the workforce of the future on all attributes of pavement preservation and sound asset management,” said Jim Sorenson, senior construction and system preservation engineer in the FHWA’s Office of Asset Management. “Opening of the NCPP brings together the resources for national level research and development in the preservation area.”

The center also will have the capability of becoming the administrator of pooled-fund studies, such as the ongoing sealer/binder research (for more information, visit http://fp2.org).

At present the NCPP personnel consists of a full-time executive director, Larry Galehouse, P.E., technical engineer David L. Smiley, P.E., and administrative manager Patte Hahn. In addition, part-time experienced staff and faculty expertise are available for the center.

For more information, contact Patte Hahn, National Center for Pavement Preservation, 2857 Jolly Road, Okemos, Michigan, 48864, 517-432-8220, fax 517-432-8223, hahnp@msu.edu, or visit www. pavementpreservation.org.

Hot Topic No. 8

Aging drivers get more attention. Positive guidance is one way to make roads safer in the future as the Baby Boomers retire, says a June report from The Road Information Program, and it’s a trend that road agencies will have to acknowledge.

“With the graying of the Baby Boom generation, the number of older drivers on the road and the amount of driving they do continues to increase,” according to TRIP’s Designing Roadways to Safely Accommodate the Increasingly Mobile Older Driver, released in June. “However, along with this increase in the number of older drivers and their level of driving has come a sharp increase in the number of fatalities involving older drivers.”

The TRIP report defines older drivers as those aged 70 and up, observing National Highway Traffic Safety Administration data showing that traffic fatality rates begin to increase in this segment.

It found the number of Americans 70 and older killed in traffic crashes increased by 27% between 1991 and 2001, while the number of overall motor vehicle fatalities increased only 2%. Florida led the nation in the number of older drivers killed in traffic accidents in 2001.

And not only are the older drivers at risk, they kill others as well. In 2001, crashes involving at least one older driver caused 5,113 fatalities nationwide, up from 4,261 persons killed in crashes involving an older driver in 1991, a 20% increase.

“Recent trends indicate that older Americans are more mobile than ever,” TRIP found. From 1991 to 2001, the number of licensed drivers age 70 and older increased 32%, from 14.5 million to 19.1 million. And the number of older Americans who continue to drive is increasing.

Based in part on its analysis of the FHWA’s Older Driver Highway Design Handbook, TRIP recommends a series of “positive guidance” actions that will enhance older driver safety, including:

Signage: Clearer and less complex signage, with larger lettering and larger pavement markings; better street lighting, particularly at intersections; higher-performing retroreflective material in signs and pavement markingings.
Intersections: Bright, luminous lane markings and directional signals; overhead indicators for turning lanes; overhead street-name signs; installation or widening of left-turn lanes.
Streets and Highways: wider lanes and shoulders to reduce the consequences of driving mistakes, longer merge and exit lanes, and rumble strips to warn motorists when they are running off roads.

The entire report is available at www.tripnet.org/ OlderDrivers2003Study.PDF.

Hot Topic No. 9

Rumble strips, permanent and temporary. The FHWA’s No. 1 safety objective, as outlined in a new 2003 highway safety initiative, is to reduce fatalities involving roadway departure crashes (run-off-road and head-ons) by 10% by 2007. This could save as many as 2,300 deaths yearly, the FHWA says.

In 2003, the FHWA has actively promoted installed rumble strips as a way to lower departure crashes. Other ways include:

Identification and correction of deficiencies in sign and pavement marking visibility.
Increased use of skid-resistant pavements.
Actively paving shoulders and eliminating edge drop-offs.

In recent years, FHWA researchers have demonstrated the superiority of milled-in rumble strips, opposed to those formed in virgin pavements. “Continuous, milled shoulder rumble strips should be installed on rural freeways and expressways on the NHS as an effective means of reducing single vehicle, run-off-road crashes caused primarily by any form of motorist inattention,” the FHWA said in a technical advisory in 2001. “While they may be installed on a project-by-project basis, economies of scale and timely implementation of shoulder rumble strips make system-wide installation projects highly desirable.”

What’s new this year is the FHWA’s attempt to get the word out to road agencies and the motoring public.

Also, the FHWA’s 2003 edge drop-off initiative — just gathering steam — is dubbed “The Safety Edge” and is dedicated to getting road agencies to eliminate pavement edge drop-offs of 3 or more inches, which are unsafe if the roadway edge is at a 90-degree angle to the shoulder surface.

The FHWA is urging agencies to adopt a standard contract specification requiring a 45-degree-angle asphalt fillet along each side of the roadway in all resurfacing projects as a simple and cost-effective way to assure pavement edge safety. It also urges routine resurfacing of shoulders when roadways are resurfaced.

An estimated 11,000 Americans suffer injuries, and 160 die each year in crashes related to unsafe pavement edges, at a cost of $1.2 billion, the FHWA says. Pavement edge treatments will saves lives, reduce agency tort liability, and reduce maintenance expenses, all for less than 1% of a pavement’s resurfacing budget.

And rumble strips are not just for shoulders. New research from the New York State DOT analyzes temporary rumble strips for use in work zones — one made from reclaimed rubber from tires — and finds they work in making work zones safer.

“The use of rumble strips at work zones is effective and should be continued,” says Rickey L. Morgan, Civil Engineer I, in his July Special Report 140, Temporary Rumble Strips. “Specifications should be modified to allow for variable spacing of the strips within a set and for the use of other types of rumble strips besides the types currently allowed.”

One type was made of strips of recycled tire tread, fastened to the pavement, which worked to researchers’ satisfaction, although questions of adhesion must be addressed. “The recycled tire tread strips have the added benefit of providing a use for old tires,” Morgan added.

Morgan concludes:

Rumble strips of 10-mm thickness +/-3 mm should be in sets of six strips spaced at no more than 2.7-m apart and preferably at irregular intervals with the spacing determined by the speed limit.

A spacing of 1.8 to 2.4 m between strips should be used when the speed limit is below 50 miles per hour and 2.1- to 2.7-m spacing when the speed limit is 50 miles per hour or greater. The irregular spacing of individual strips will eliminate the regular beat and feel of pavement joints. The wider spacing will provide drivers of vehicles at the higher speed limits sufficient time to realize an upcoming change in driving conditions.

The installation of rumble strips should closely follow the specifications of both air and pavement temperatures, presence of moisture, cleaning of pavement, and method of adhesion to survive the anticipated duration in service.

Rumble strip resources are available at http://safety.fhwa.dot.gov/programs/rumble.htm.

Morgan’s paper on temporary rumble strips may be downloaded at www.dot.state.ny.us/tech_serv/ trdb/files/sr140.pdf.

And for more information on edge drop-off remediation, contact Harry W. Taylor, FHWA’s Office of Safety Design, 202-366-2175, Harry.Taylor@fhwa.dot.gov.

Hot Topic No. 10

Eyes in the skies will boost roadways, Aerial and satellite remote sensing is a rapidly growing arena of activity that will be of great benefit to the transportation infrastructure community as it develops. These systems also include unmanned aerial vehicles and pole-mounted video systems.

In a Report of a Conference Committee for Conferences on Remote Sensing and Spatial Information Technologies for Transportation, held in Washington, D.C., December 2001, David S. Ekern, Minnesota DOT, and conference committee chair outlined the benefits.

Collecting remote sensing information is nonintrusive. “Transportation agencies are always looking for ways to improve employee safety and to minimize the amount of time employees spend on the roadway dodging traffic,” Ekern said.

Information gathering is potentially quicker, cheaper, and better with remote sensing.

Remote sensing provides access to places that are impossible or too expensive to reach with other methods and provides a synoptic [general overall] view.

The technology delivers the ability to collect continuous information at a low cost.

Both spatial [geographic] and spectral accuracy is improving in remote sensing as its cost is decreasing.

Because only 5% of the National Highway System is instrumented, Ekern said, remote sensing offers a low-cost potential for monitoring the remainder of the system.

Remote sensing is particularly opportune for transportation environmental assessment and streamlining, operations, including ITS, security, identification of roadway characteristics, and performance measurement.

Satellites already are deeply entrenched in design of the road system. Color or infrared satellite imagery of a job location already may be acquired from private sector firms in digitized or customized form, and provided in archived, near-real-time, and real-time availability.

Most likely, in the near future, virtual-reality programs will convert this spatial data into virtual-reality objects, which can be overlaid by road maps, digitized imagery, or topographic maps.

And this virtual highway will be valuable not only to designers, but to construction inspectors, who could use satellite images layered on a top model to inspect progress of traffic loads, environmental compliance, or construction progress, even the patterns of asphalt compaction.

Reprinted from Better Roads Magazine
December 2003