Highway Work Zones: Smart and Smarter

Highway Work Zones: Smart and Smarter

From the June 2007 issue of Better Roads Magazine منبع

Tom Kuennen, Contributing Editor

Lasers, radar, GPS, Intelligent Transportation Systems, and even nanotechnology are shaping today’s work zones.

Technologies of the future are shaping today’s work zones, making them safer for motorists and workers, more easily navigable, and in some cases, completely removing traffic-control personnel like flaggers out of the path of danger.

It’s being driven by a combination of dedicated researchers, innovative manufacturers, interested state DOTs, and game contractors, all following the lead of national entities like the Federal Highway Administration, American Association of State Highway & Transportation Officials, ITS America, and the American Traffic Safety Services Association.

And it’s involving computers, lasers, radar, global positioning systems, intelligent transportation systems, and ultimately, nanotechnology, as applied to traffic control in general and work zones in particular.

Radar, Dynamic Message Signs Serve Drivers

In Illinois, this Real-Time Traffic Control System consisted of dynamic message signs, traffic sensors, and portable cameras linked to a base station server.

For example, the Georgia Department of Transportation is supporting research on smart work zones on interstates using sensors to measure traffic density and speed, and calculating how they could affect traffic flow. The information is then transmitted via computer to traffic advisory signs located over interstates in metro Atlanta.

In the meantime, Georgia is sending real-time work-zone information, including delays, to Web-

و............enabled mobile phones and PDAs, so the information is accessible within

Highway Work Zones: Smart and Smarter

Road Science

From the June 2007 issue of Better Roads Magazine

Tom Kuennen, Contributing Editor

Lasers, radar, GPS, Intelligent Transportation Systems, and even nanotechnology are shaping today’s work zones.

Radar, Dynamic Message Signs Serve Drivers

In Illinois, this Real-Time Traffic Control System consisted of dynamic message signs, traffic sensors, and portable cameras linked to a base station server.

In the meantime, Georgia is sending real-time work-zone information, including delays, to Web-enabled mobile phones and PDAs, so the information is accessible within the automobile itself.

Arkansas is investing in automated work-zone information systems that not only give motorists delay and closure information, but specify alternate routes. The Michigan DOT is experimenting with variable speed limits in work zones to ensure more consistent speeds throughout work zones during non-peak traffic periods. And Illinois is using van-enabled photo enforcement to keep speeds down in work zones.

They’re all a part of today’s world of smart work zones.

What are smart work zones?

While enhancements to work-zone safety are broader than the field of Intelligent Transportation Systems alone, it is ITS that promises the greatest improvements in traffic flow.

Using ITS in work zones can improve safety and lessen the delay that can come from reduced capacity and incidents, the FHWA reports in its January 2007 document, Intelligent Transportation Systems for Work Zones: Deployment Benefits and Lessons Learned. "When work zones use ITS tools in conjunction with sound planning, traffic control, coordination, communication, and impacts estimation, work-zone operations can be greatly enhanced and the management of traffic in the work-zone area made more efficient," the FHWA said.

For example, a study of successful technology deployments determined that:

Between 50 and 85% of drivers surveyed said that they changed their route at least sometimes in response to travel time, delay, or alternate route messages provided by work-zone ITS.
Reductions in queue lengths from 56 to 60% are possible, with simulations indicating system-wide reductions in total delay may range from 41 to 75%.
Speed monitoring displays reduce speeds in work zones by four to six miles per hour. One study found a 20 to 40% reduction in vehicles traveling 10 miles per hour or more over the speed limit when they were used.

A 2004 Federal Highway Administration survey of ITS deployment found that, of the 43 states who responded, 20 states used ITS in work zones. Findings from this survey showed:

19 states used portable dynamic message signs, 14 used permanent dynamic message signs, eight used highway advisory radio, five used temporary speed limits, and four used a series of warning signs activated progressively farther from the work site as sensors detect increases in traffic volume.
When asked why they chose to deploy ITS in work zones, 16 states indicated it was to reduce congestion, and 17 said it was to reduce crashes.

Challenge of work zones

Highway work zones constitute a major safety concern for government agencies, legislatures, the highway industry, and the traveling public. But despite the efforts made by government agencies and the highway industry, and growing traffic volumes, there is little indication that work-zone crashes are on the decline nationwide.

At the University of Nebraska-Lincoln, a robotic road sign is under development, controlled by two electric motors, one of which drives the robot, while the other is used to steer the robot, both using worm gears.

According to National Institute of Occupational Safety & Health data for 2005, issued in August 2006 and the most recent firm data available, fatal highway incidents remained the most frequent type of fatal workplace event, accounting for one in every four fatalities nationally in 2005. Fatal highway incidents rose by 2% in 2005, accounting for 1,428 worker deaths. The number of workers who were killed after being struck by vehicles or mobile equipment rose from 378 in 2004 to 390 in 2005.

There were 1,074 work-zone fatalities in the U.S. in 2005, the most recent year for which firm data are available, reported the American Traffic Safety Services Association. That’s up from 1,068 in 2004 and 1,028 in 2003.

Even worse, studies show that while motorists think workers are at most risk, the reality is by far the majority of those fatalities are motorists; in 2005, over four out of every five work-zone fatalities were motorists.

"Work zones are part of the American landscape," said ATSSA president Pete Speer, and vice president of sales, Filtrona Extrusion Traffic Control Products, Tacoma, Washington. "They are here to stay as our roadways undergo continued maintenance and upgrades. We encourage motorists to slow down, be patient, be aware, and expect the unexpected."

Threat of the unexpected

Unfortunately, it is the unexpected that highway workers face in our work zones. For example, the job of flagger, readers may know, is one of the single most dangerous jobs in the country.

A banner for National Work Zone Awareness Week 2007 supports safer roads and better traffic flow for drivers.

Highway workers routinely work in proximity to construction vehicles and motor vehicle traffic. Flaggers and other workers on foot are exposed to the risk of being struck by traffic vehicles or construction equipment if they are not visible to motorists or equipment operators. Workers who operate construction vehicles or equipment risk injury due to overturn, collision, or being caught in running equipment. Highway workers, regardless of their assigned task, work in conditions of low lighting, low visibility, and inclement weather, and may work in congested areas with exposure to high traffic volume and speeds.

Standardization of work-zone areas is set by the FHWA for both traffic control and work-zone safety devices. All national safety standards to control traffic through work zones are contained in the Manual on Uniform Traffic Control Devices. The FHWA has responsibility for the MUTCD, and also for the NCHRP 350, which contains the federal standards and guidelines for all work-zone safety devices.

Keeping national standards current with the latest technology is an ongoing process, so the FHWA began updating its national guidelines on planning and implementing work zones. The final rule on Work Zone Safety and Mobility was published in the Federal Register on September 9, 2004 with an effective date of October 2007. It attempts to address the changing times of more traffic, more congestion, greater safety issues, and more work zones.

Roboflagger AFAD is on duty in Washington State.

The National Work Zone Safety Information Clearinghouse, http://www.wzsafety.tamu.edu, is an example of a successful educational outreach tool that reaches the public and the highway community. Started in 1998 by the FHWA and American Road & Transportation Builders Association, this clearinghouse is the first centralized, comprehensive work-zone information resource.

Work Zone Awareness Week 2007

Just recently, National Work Zone Awareness Week 2007 was observed April 2-6 across the country. Kicking off the week was a media event on April 3 near the new Woodrow Wilson Bridge outside of Washington, D.C., hosted by the Virginia DOT.

With a theme of Signs of Change, this year’s week demonstrated that today’s work zones produce tomorrow’s improved roadways, resulting in smoother rides, better traffic flow, and safer travel. At the same time, motorists were reminded that they should slow down and be alert to signs indicating changing conditions as they travel through work zones.

Motorists are advised they are entering a work zone with camera-enforced speed limits.

More is being done. To help younger drivers, the FHWA produced Moving Safely Across America, an interactive CD that has been distributed to 15,000 driver-education teachers. Part of this CD includes how to safely drive through work zones. The FHWA has also completed a series for new drivers, to increase their awareness of work zone hazards, and provides tips for safely negotiating work zones.

These materials are packaged as the Turning Point campaign being developed through a contract with ARTBA. The content includes a safety video, an interactive training tool, a resources library for trainers, an instructor’s guide, promotional materials, and a Web site. Innovative materials such as the interactive training tool, which puts new drivers behind the wheel in work zones, are expected to get widespread use by computer-savvy teens. It’s expected that 5,000 toolkits with the campaign materials developed in this project will be distributed to driving instructors and DOTs.

The FHWA also provides work-zone training courses for highway engineers. And for the technical highway safety community, the FHWA distributes a Best Practices Guidebook (available at http://ops.fhwa.dot.gov/wz/index.asp, or on a CD) that highlights good work-zone practices of state transportation agencies throughout the U.S. Quickzone is a software decision-making tool that helps engineers improve work-zone safety and mobility.

Kansas sets the stage

The understanding of exactly what goes on in the work-zone accident was enhanced in June 2006 by the comprehensive study, Determining Major Causes of Highway Work Zone Accidents in Kansas: Final Report, sponsored by the Kansas DOT and the University of Kansas Center for Research in Lawrence.

Kansas researchers Bai and Li took a four-step approach in this research. A literature review of work-zone crash studies was conducted to establish a base of understanding, then crash data from the Kansas DOT accident database and the original accident reports were compiled, resulting in a total of 157 fatal crash cases between 1992 and 2004.

Then, using the collected data, the researchers systematically examined the work-zone fatal crashes and the unique crash characteristics and risk factors in the work zones were determined.

They found:

Male drivers cause about 75% of the fatal work-zone crashes in Kansas. Drivers that are between 35 and 44 years old, and older than 65, are the high-risk driver groups in work zones. In addition, a majority of the nighttime crashes were caused by drivers younger than 55.
The daytime non-peak hours (10 a.m. to 4 p.m.) were the most hazardous time period in work zones by accounting for 32% (highest hourly rate) of the fatal crashes. Nighttime (8 p.m. to 6 a.m.) had 37% of the crashes.
Work zones on rural two-lane highways with speed limits from 51 to 70 miles per hour were high-risk locations, accounting for 59% of the fatal crashes. Work zones located on complex geometric alignments were more hazardous, with half of the fatal crashes.
Most (68%) of the crashes were multi-vehicle crashes. Among the multi-vehicle collisions, head-on, angle-side impact, and rear-end are the three most frequent collision types. In addition, analyses show that the most severe crashes frequently involved heavy trucks: 40% of the crashes were caused by heavy trucks and almost all of these crashes involved multiple vehicles.
Human errors, including inattentive driving and misjudgment or disregarding of traffic control, were the top killers in work zones.
Inclement weather conditions and unfavorable road features (interchange areas, intersections, ramps, etc.) do not significantly contribute to fatal work-zone crashes.
Improved traffic control is the most direct method to reduce highway work-zone fatalities. More effective and sufficient work-zone traffic controls should be installed. In particular, they found, there is an urgent need to develop speed-control methods that can be strictly enforced in the work-zone areas.
Improved traffic control is the most direct method to reduce highway work-zone fatalities. More effective and sufficient work-zone traffic controls should be installed. In particular, there is an urgent need to develop speed-control methods that can be strictly enforced in the work-zone areas.

Camera-enforcement in Illinois

In line with the Kansas conclusions, all states recognize that control and reduction in work-zone speeds is paramount to improving safety. In Illinois this year, high-tech speed-photo enforcement vans under the aegis of the Illinois State Police are using cameras to nab work-zone speeders.

Camera-enforced speed monitoring in the work zone is announced with signage up front. The vans — which rotate among different projects — automatically shoot photos of speeders who exceed the standard limit of 45 miles per hour on interstates. A letter follows imposing a fine or worse.

From July 2006 — when the program started — the vans have caught 4,000 drivers. Fines are $375 for the first offense, and $1,000 for each succeeding ticket, along with a loss of driving privileges for 90 days.

Last year, three vans rotated among high-traffic construction sites in the Chicago area and downstate, which in Illinois means everything in the 370 miles south of Chicago. This summer, the fleet will grow to four vans. The vans only operate when workers are present.

A vendor is providing the equipped vans to IDOT, and was training the Illinois State Police and DOT personnel on how to use the system. The overall goal is to determine the effectiveness of speed-photo enforcement in work zones. Data are being collected on speed, speed variation, speeding tickets issued, and fraction upheld as valid in courts, reports the Illinois Center for Transportation at the University of Illinois at Urbana-Champaign.

Leased radar and signage

Since 2000, applications of smart work zones have proliferated. An early example was a system in use on a 40-mile work zone for the major bridge and highway reconstruction along I-55 south of Springfield. This Intelligent Transportation System, dubbed the Real-Time Traffic Control System, consisted of 17 remotely controlled portable dynamic message signs, eight portable traffic sensors, and four portable cameras linked to a base station server via wireless communication. The system covered the work-zone area as well as the northbound and southbound approaches to the work zone.

Retroreflective materials continue to improve; Omni-Brite S-9000 is a flexible microprismatic material.

The traffic sensors used X-Band radar to automatically collect vehicle speed and presence data, which were transmitted to a central base-station server. The central server calculated volume and traffic speed, and generated predetermined messages based on the level of traffic congestion.

Real-time traffic conditions such as delay information and lane closure advisories were automatically transmitted and displayed on the portable DMS and Illinois DOT’s Web site. The system updated the Web site every five minutes based on congestion levels in the work zone. IDOT staff was automatically notified of congestion and incident detection alerts. Images from the portable cameras were used to confirm data generated by the system. Solar arrays provided power source for the battery-operated roadside equipment.

The system was designed based on the state DOT staff’s developing a set of functional requirements, and then comparing the approach proposed by the vendor. After finalizing the system design, the resulting system was leased by the prime contractor from a firm specializing in work-zone systems.

The DOT reported significant cost savings by leasing the system as a bid item. The cost of leasing the system was $785,000, which represented approximately 2% of the total reconstruction contract cost of $35 million. The system was deployed for a total of 16 months from February 2001 to May 2002.

The lease included a provision for contractor personnel to monitor the system and provide 24-hour maintenance support. The system operated in an automatic mode; however, one person was assigned to check system performance periodically during weekdays. After hours and during weekends, contractor personnel were on-call to handle problems. The terms and conditions of the lease agreement stipulated fines for system deficiencies if not corrected within a specified time.

Communication via the Internet

Illinois isn’t the only state using the Internet to facilitate work-zone navigation and condition reporting. In a growing number of states, real-time work-zone conditions are available on the Internet. Like state and local Road Weather Information Systems — that can be accessed on the Internet on a state-by-state basis, among those states which maintain them — the work-zone status sites provide a tremendous service to the drivers and taxpayers who are aware of them (see High-Tech Helps Tame Road-Weather Woes, September 2006, pp 32-44, or visit http://www.betterroads.com.

One of the earliest was Georgia Navigator, an Internet Web site developed by the Georgia DOT to provide real-time traffic information. The Web site was first created during the 1996 Olympics and then enhanced in 1998. The Web site, www.georgia-navigator.com, provides advance road work and lane-closure alerts, in addition to standard traffic-flow reports.

Its My Navigator features lets a patron create a personal traffic page using Navigator’s maps, traffic cameras, trip times, and more, or set up an e-mail Traffic Alert account to receive e-mail notification of incidents in the area. Best of all, Navigator To Go permits the user to access the Navigator Web site (or personal traffic page) to access incident listings, construction reports, and trip times using a Web-enabled mobile phone or personal data assistant device. Also, mobile phone users can speak to a live traffic operator about conditions along the route by using quick-touch codes.

Dynamic lane merge in Michigan

The FHWA reports that dynamic lane merge is an ITS technology that can be used in work zones to alleviate the congestion and crashes this mix of reactions can cause. The technology uses electronics and communications equipment to monitor traffic flow and, as queuing increases at approaches to lane closures, regulate the merge, requiring either early merge or late merge depending on traffic conditions.

In the summer of 2003, the FHWA said, the Michigan DOT deployed an early merge system. When traffic conditions exceeded preset limits on traffic volume, vehicle speed, and detector occupancy, the system activated and a Do Not Pass message was displayed. When Michigan DOT and Wayne State University assessed the impacts of the DLM system, they found:

Average travel speed increased from approximately 40 miles per hour to 46 miles per hour during the morning peak period.
An average of 1.2 crashes per month occurred in the four months prior to activation; after activation, no crashes were reported.

The cost to MDOT, which leased the system, was $120,000, including design, installation, calibration, and maintenance. The cost to redeploy the system at additional work zones, which includes furnishing the devices in operable condition, initial installation, operation, inspection, maintenance, cleaning, and removal at project completion, was about $30,000.

The Minnesota DOT initiated several projects to study the benefits of DLM using a late merge system, the FHWA reported. MnDOT found that:

The late merge system eliminates confusion over lane use issues and the correct merge point.
Merge instructions on portable dynamic message signs aided in eliminating aggressive driving behavior.
Near equal usage of both lanes equalized speeds between lanes.
Increased usage of the discontinuous lane decreased total queue lengths by 35%, but vehicle volume through the construction zone was not changed.

Roboflagger and the AFADs

Between 1999 and 2005, there were 47 work-zone deaths in Washington State and 4,444 work-zone injuries. Speeding and inattentive driving are the two major reasons for work-zone collisions, and flaggers are the most at-risk workers. But in February 2007, a new kind of flagger appeared in Washington State; that is, there was no flagger at all.

Instead, roboflagger was on the job. The roboflagger is a 12-foot-tall steel device with automatic arms and lights remotely operated at a safe distance by a human flagger behind traffic safety barriers.

Washington DOT maintenance crews have used the roboflagger on projects in the Tacoma area, but February marked the first time the roboflagger was tested on a construction project. Through late March, crews would install 1.2 miles of guardrail on U.S. 2 just west of Monroe, with one lane closed from 8 p.m. to 5 a.m. each night while a pair of roboflaggers would help alternate traffic through the work zone. Drivers tend to go fast in the area with speeds in excess of 60 miles per hour.

"This is a great project for us to test out the roboflagger," said Carl Barker, assistant project engineer, in February. "We’re working at night, when visibility is low, and we’re alternating traffic on a two-lane highway. We’ll be able to see how the roboflagger works in these conditions, and how drivers and our crews respond to it."

In April 2007, by project’s end, the roboflagger got a thumbs-up from both the state and the contractor.

"It was a vital tool for doing traffic control at night," said Mark Smith, a flagger working for Dirt and Aggregate Interchange, the Washington DOT contractor on the U.S. 2 French Creek project. "Any flagger who tried to stop people with a paddle in this area would have had to be sedated to remain there."

The human flaggers themselves said roboflagger worked well. Human flaggers were close enough to step in to wave emergency vehicles through, but far enough away to remain safe. They also report roboflagger’s height allowed more drivers to see the work zone farther back. That meant no rear-end accidents in the work zone.

"Local drivers did the right thing most of the time," said Denise Smith, the contractor’s flagger. "One or two folks said when they saw the flagger sign and failed to see a person, they kept going. I think the more we use roboflagger, the more drivers will recognize it as a sign to stop."

What really impressed the team was roboflagger’s ability to keep working despite huge downpours and dense fog. "The lights are so bright and the flagger is so tall, drivers were able to see the work zone well in advance," Smith said. "The fog was so dense at times, a human flagger would have had to pack up and come back the next day."

AFADs get the OK

Washington State’s roboflagger is an example of an AFAD, an Automated Flagger Assistance Device, and their use on highways is only a few years old.

In Washington State, roboflagger provided enhanced visibility under nighttime conditions.

AFADs are portable traffic-control systems that assist a flagger operation for short-term lane closures, on two-lane highways. The AFADs are used to remove one or both flaggers, in a typical flagging operation, from the traveled way in TTC zones. Flaggers operate AFADs by using a radio-control unit or by using a cable directly attached to the AFAD. In either case, the flaggers can be positioned well away from the roadway and moving traffic.

The FHWA’s interim approval of AFADs in 2005 resulted from research on different applications in different states. Three specific AFADs underwent extensive formal experimentation under the MUTCD, and were deemed by the FHWA to be successful under the conditions tested:

Autoflagger, a STOP/SLOW system, was studied by the Minnesota DOT.
The J4 Flagger Workstation, another STOP/ SLOW system, was studied by the Illinois DOT.
RC Flagman, a Red/Yellow Lens, was studied by the Ohio, Missouri, Wisconsin, and Alaska DOTs.
The next step in implementation beyond the interim approval will be the addition of AFADs to MUTCD as a part of the formal rulemaking process for the next edition of the MUTCD, which is currently scheduled to be issued in 2008.

Now that AFADs are going mainstream, Intellistrobe Safety Systems, of Springfield, Missouri, produces the WS1-AGTM Automated Flagger Assistance Device, a remote-controlled flagging system operated by a worker in a roadway work zone. The device guides traffic with stop and go lights placed at each end of a work zone.

Other high-tech developments are helping flaggers and other work zone personnel. For example, retroreflective materials continue to improve. Omni-Brite S-9000 from Avery Dennison is a flexible microprismatic material designed for use on safety vests and other garments. It offers high levels of reflectivity no matter which way road workers turn, twist, or bend. It’s machine washable and has been certified to meet or exceed many industry standards. A sister product is a flexible, microprismatic material suitable for conversion into cone collars and similar products.

Robot signs, barrels

In December 2004, we reported that construction work zones will get a good deal safer if self-propelled orange barrels for use in slow-moving maintenance operations and active work zones are implemented, according to developer Dr. Shane M. Farritor, an assistant professor in the Department of Mechanical Engineering, University of Nebraska-Lincoln.

These self-propelled barrels look like conventional barrels, but have a robotic three-wheeled base.

These self-propelled barrels look like conventional barrels, but have a robotic three-wheeled base. Farritor’s plan is for the barrels to be delivered to the roadside by a specially equipped truck, from which an operator controls their deployment using a laptop computer. Each fleet of robots is made up of a motorized lead robot — or shepherd — which is equipped with a GPS receiver and less-expensive motorized barrels. A camera on the truck sends an image of the pavement to the laptop, and an operator directs the barrels by indicating on the computer screen where the barrels should go. The barrels also can move on their own.

The motorized base of each unit has two electric motors which are powered by a 12-volt lead-acid battery. These drive two 7.9-inch-diameter wheels, which permit the barrels to move in any direction. They can move at a speed of 4 feet per second.

The software then calculates the GPS coordinates for the location where the shepherd ought to be placed, and this location is sent to the shepherd via a radio link. The shepherd unit moves into position, then informs the other barrels by radio where to go. These slave units use dead reckoning, such as counting how many times their wheels turn, for instance, to work out their position. Finally, the shepherd confirms that its charges are correctly positioned by using a laser-based radar system to correct errors. This laser system also can evaluate if a barrel keeps moving out of place; it can move it out of the operation and close it down.

Independent, autonomous barrel motion has several advantages, Farritor told Better Roads. First, the barrels can self-deploy, eliminating the dangerous task of manually placing barrels in busy traffic. Second, the barrel positions can be quickly and remotely reconfigured as the work zone changes. Barrels could continuously follow work crews to maintain optimal placement for safety.

Now, in 2007, Farritor and his colleagues are developing a robotic road sign. Since signs have such a large surface area, they are more susceptible to being toppled by wind gusts. This physical characteristic is taken into account in the design of the robotic road sign. When a mesh sign is mounted, the stand allows for stability in wind gusts up to 70 miles per hour.

The robotic road sign is controlled by two electric motors. One motor is used specifically to drive the robot, while the other is used to steer the robot. Worm gears are used for driving and steering the robot, and are selected due to their ability to act as brakes and stop devices quickly. With the designed gear ratio the robotic road sign can travel with a speed of up to 2.5 miles per hour.

Nanotechnology meets work zones

Nanotechnology has just begun to impact highway materials and construction. The unusual properties of nanomaterials have revealed a great opportunity for the development of new sensor systems and smart construction materials for surface transportation.

An earlier Road Science article discussed the potential nanotechnology applications in highway pavements in two categories: smart materials for pavement and bridge construction, and sensors for transportation and pavement infrastructure condition monitoring (see Small Science Will Bring Big Changes To Roads, July 2004).

A van-mounted unit for camera enforcement of speed limits in Illinois work zones.

"Nanotechnology will lead to signs that will be able to shed water," said Dr. Richard A. Livingston, senior physical scientist, at the FHWA’s Advanced Infrastructure Research program.

"Existing coatings tend to accumulate grime, which reduces visibility and degrades the materials over time," Livingston told Better Roads. "Researchers have created plastic layers that have a nanoscale of roughness that will repel water and dirt, modeled after the coating of the lotus leaf."

The lotus leaf, or water lily leaf, exhibits an extraordinary ability to keep itself clean and dry. Now nanotechnology is being used to mimic the lotus leaf surface and create new products that outperform existing no-stick products, and it’s clear that this technology will have immediate benefits for traffic and work-zone signage.

Typically, on a hydrophobic (water-repellent) easy-clean surface, particles of dirt are just moved around by moving water. But on a Lotus Effect surface, dirt and grime are collected by water drops and rinse off.

It’s only a matter of time until the nanotechnology challenges are solved so that this technology can be brought to the market for use with traffic signs and, in particular, traffic control devices, which require labor-intensive, periodic washing to remove road grime and enhance visibility.

To study this effect further, in 2006, researchers at the University of Houston developed and monitored the condition of a stop sign using nano sensors designed for transportation and pavement infrastructures.

In the stop sign demo, nano sensors, including a magnetometer, accelerometer, and a wireless MEMS, were used to monitor the condition of a stop sign. The monitoring included orientation change, tilt-angle change, and existence. Researchers found that with this technology, if the stop sign is turned, tilted, or removed, the system will report these conditions to its maintenance office wirelessly.

Smart work-zone software

Smart work zones have spread into design software, where new programs help states design, implement, and control work zones within the DOT, but also among cities, counties, and contractors.

One such program is ConeZONE, from SignCAD Systems of Minnetonka, Minnesota.

ConeZONE is said to be the traffic industry’s only automated and fully integrated system for work-zone design and management.

ConeZONE uses its dynamic arrangement engine to select devices and configurations from state approved lists and standards and to automatically place them with GPS locations into the work zones, so they can be properly installed and mapped.

The software is aimed at enhancing safety and mobility, placing the design and implementation of traffic work zones into the hands of the state DOT. ConeZONE includes eight modules that integrate fully to provide a seamless platform for coordination and communication among all users across the Web and over LAN networks.

Integrated modules include SignCAD, SignCAM, SignTRACK, Path Planner Roads, Document Tracking Module, Work Order Module, and Vehicle Simulation. When these modules are implemented, the software becomes a Web-based suite of integrated applications that allows all agencies throughout the state to have their traffic-control plans automatically written and coordinated with all of their work-zone activities.

ConeZONE automatically designs each work zone and runs simulations to test for mobility and safety; generates work orders for the DOT, municipalities, and for each contractor; keeps work-zone standards and approved devices current for all users via its Web repository; automatically documents all work-zone activity, all permits, inspections, and incidents via Web interface for all users; and inventories, tracks, and manages all objects and devices in the field. States using ConeZONE can distribute it free to cities, counties, and contractors.

For More Information

The new technical paper, Determining Major Causes of Highway Work Zone Accidents in Kansas: Final Report, is available at www.iri.ku.edu/publications/Report_Bai.pdf.
A workshop on ITS in Work Zones was held in St. Louis in September 2005, and remains a treasure chest of resources for the traffic professional. View and download .pdfs of the presentations on AASHTO’s Web site at www.transportation.org/?siteid=42&pageid=1949.
FHWA’s Technical Provisions for Automated Flagger Assistance Devices may be reviewed at http://mutcd.fhwa.dot.gov/HTM/2003r1/afad/afad_tech012705.htm.
A detailed 2004 analysis, Fatal Occupational Injuries at Road Construction Sites, uses older data, but still is valuable due to the patterns it reveals. See it on the Web site of the Bureau of Labor Statistics at www.bls.gov/opub/mlr/2004/12/ressum2.pdf.
NIOSH’s page on Traumatic Occupation Injuries: Highway Work Zones may be visited at www.cdc.gov/niosh/injury/traumazone.html, and contains a host of valuable publications.
Explore Georgia DOT’s superb Navigator Web site at www.georgia-navigator.com.
The National Work Zone Safety Information Clearinghouse http://wzsafety.tamu.edu is a powerful resource for the industry.
The FHWA document describing Illinois DOT’s use of X-band radar to detect and analyze traffic movement through the I-55 Lake Springfield work zone is available at www.itsdocs.fhwa.dot.gov//JPODOCS/REPTS_TE/13984.htm.
The Texas DOT-sponsored nanotechnology research at the University of Houston, Nanotechnology Synthesis Study, in which a nanotech-equipped stop sign was studied can be viewed at
ftp://ftp.dot.state.tx.us/pub/txdot-info/rti/psr/5239.pdf.
The Web page Intelligent Transportation Systems for Work Zones: Deployment Benefits and Lessons Learned is loaded with applications and can be found at www.its.dot.gov/jpodocs/repts_te/14320.htm#b1.
The 177-page National Cooperative Highway Research Program Report 500, Guidance for Implementation of the AASHTO Strategic Highway Safety Plan, Volume 17: A Guide for Reducing Work Zone Collisions, released in 2005, may be downloaded at
http://www.cutlerrepaving.com
http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_500v17.pdf.

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