Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Automated system installs pavement markers

12.01.2007
System improves safety for road crews and drivers

On rainy nights in Georgia and across the nation, drivers greatly benefit from small, reflective markers that make roadway lanes more visible. A new automated system for installing the markers is expected to improve safety for workers and drivers.

There are more than three million of these safety devices, called raised pavement markers (RPMs), in service on Georgia highways. They are installed and then need to be replaced about every two years by road crews who consider the task one of the riskiest they face. Workers typically ride on a seat cantilevered off the side of a trailer just inches from highway traffic.

Manual RPM placement is not only risky for personnel, but it is also expensive and time-consuming. A typical RPM placement operation includes four vehicles and a six-person crew. All the vehicles must stop at each marker location, so there is tremendous wear on the equipment and increased fuel use.

The Georgia Department of Transportation (GDOT) believed there was a better way to do it and funded the Georgia Tech Research Institute (GTRI) to develop a first-of-its-kind system capable of automatically placing RPMs along the lane stripes while in motion. After almost three years of research and development, GTRI expects to deliver a prototype system early this year. Because of widespread interest in the system, researchers will present a report on their project on Jan. 23 at the National Research Council's Transportation Research Board Annual Meeting in Washington, D.C.

"The advantages of our automated system are: it's less labor-intensive, it's faster and safer, uses less fuel, and it causes less wear and tear on GDOT equipment," explained project manager Wiley Holcombe, a GTRI senior research engineer.

Engineers conducted the work in two phases. First, they designed an RPM-placement mechanism using pressure-sensitive adhesive and a lane-stripe tracking system. Then, they developed a full-scale, truck-mounted RPM placement system. It is based on a single GDOT-owned truck and includes the lane-stripe tracking system, and electrical power, compressed air, hydraulic power, and adhesive melting and dispensing systems. Some components of the system were off-the-shelf parts, but the GTRI Machine Services shop fabricated most of the custom components for the system, Holcombe notes. After some field-testing, the project resulted in a prototype system capable of dispensing an RPM onto the pavement along with the necessary hot-melt adhesive applied at 380 degrees Fahrenheit while traveling at 5 miles an hour. A pattern-change mechanism can position two placement mechanisms to accommodate any of GDOT's five specified RPM placement patterns, Holcombe explains.

Operation of the system only requires two people. An operator on the back of the truck loads the adhesive melters with adhesive and stacks RPMs in the hoppers from which they are dispensed, depending on the placement pattern. Meanwhile, the driver of the truck must maintain alignment between the stripe pattern on the road and a caster wheel on a boom in front of the truck. Also, the driver touches a computer screen in the cab to indicate to the placement system the new stripe pattern each time the caster wheel crosses a stripe pattern change.

RPMs are dispensed from the hoppers onto a loader arm, which deposits them onto a telescoping slide that connects to a placement mechanism on an attached carriage. The carriage has a 3-foot range of travel and is moved laterally to keep the placement mechanism centered along the road stripe. RPMs are then typically applied about 80 feet apart. It takes about 35 milliseconds from the time the edge of the RPM hits the ground to the time it's flush with the road, Holcombe notes.

"The GDOT's primary use for the automated RPM placement machine will be placing markers on the skip lines for interstate and multi-lane highways," said GDOT spokeswoman Karlene Barron. "These types of routes pose the highest safety risks to our employees and equipment.

"The GDOT also plans to use the system on high-traffic-volume secondary or two-lane roads, when possible," Barron added. "Using the automated system, we will not have to stop at every placement, which will increase safety and productivity plus reduce wear and tear on GDOT equipment. Plus the operator will be high on the back of the machine instead of near ground level."

Six of GDOT's seven district offices have their own RPM placement crews, and there are four other crews that work statewide. GDOT also plans to use the system in the metro Atlanta area.

GTRI's automated raised pavement marking system could be used outside Georgia, though Holcombe explains that its design is most appropriate for Southern states with warmer climates. In regions that get a lot of snow, RPMs must be applied somewhat differently to reduce the risk of damage to RPMs by snow-clearing equipment.

Jane Sanders | EurekAlert!
Further information:
http://www.gatech.edu

More articles from Transportation and Logistics:

nachricht Study sets new distance record for medical drone transport
13.09.2017 | Johns Hopkins Medicine

nachricht Researchers 'count cars' -- literally -- to find a better way to control heavy traffic
10.08.2017 | Florida Atlantic University

All articles from Transportation and Logistics >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>