Special to The Daily Reporter
Along with death and taxes, summer road construction is one of life’s few guarantees for Wisconsinites.
That means road workers on heavily traveled arteries, sometimes just feet from traffic.
Technology offers new devices to keep both construction workers and drivers safe.
Sign of the times
One such safety device is the portable digital traffic sign. These signs, which give drivers traffic updates about upcoming work zones, are now being hooked up to sensors along highways to measure speed and volume of traffic.
These signs can give drivers pointed messages — such as “traffic stopped ahead” or “traffic slow ahead” — depending on the traffic and work-zone conditions.
“That really can have a potential to reduce rear-end crashes and other crashes in the work-zone area,” said Tom Notbohm, a traffic engineer of design with the Wisconsin Department of Transportation and a member of the Smart Work Zone Deployment Initiative, a cooperation among states throughout the region to investigate better ways to control work zone traffic.
“If things are getting congested, the signs can give drivers an opportunity to choose an alternate route, (reducing) the exposure of the workers to traffic,” he said. “We have been trying to make more use of that type of technology, especially on some of the freeway projects on critical roadways that have the highest traffic volumes and speeds.”
But such technology is more expensive than traditional, nondigitized signs. Another challenge on some sites is how the sensors relay traffic data to the digital signs.
“In a lot of cases, we have to rely on cellular phone technology,” Notbohm said. “And sometimes the signals are not very strong and don’t always work in certain areas.”
WisDOT is examining electronic speed board signs that allow the speed to change on the sign without changing the actual sign, according to Bob Emmerich, president of Safe-Con LLC, a construction safety consulting firm in Madison.
“They may require a speed reduction during the day when workers are present,” Emmerich said, “but they would allow the speed to go back up maybe at night when the workers aren’t present and they don’t consider it to be a danger to let the traffic move at a high rate of speed.”
The concept of having varying speed limits in work zones during a 24-hour period is being discussed among WisDOT and state patrol officials.
“What we have been trying to do is reduce speeds in work zones when (workers) are there,” Emmerich said.
“Our state laws are very weak on that, and it comes down to decisions by managers within the DOT.
Although, over the last couple of years, there has been a lot more reductions put into place.”
Online option allows for planning
One technology WisDOT is using is nowhere near any road construction worker or roadway. It is on the Internet at www.511wis.gov. The Web site is part of the national 511 traffic information system.
Field engineers and contractors feed the system lane closure information. As a result, the site gives drivers real-time details such as a description of construction work and times and dates work may affect travel.
The system is reliable in most cases, but is only as good as the data entered, said Todd Szymkowski, deputy director of the Wisconsin Traffic and Operations Safety Laboratory at the University of Wisconsin-Madison.
“If our sources of data are bad … there are a lot of opportunities for errors along the way,” he said. “It’s a piece of the puzzle. The 511 system provides an umbrella that brings it all together.”
Remote flagging feature flies
Another technical safety device under consideration is the remote mechanical flagger. Such devices warn drivers of work zones with traffic-control lights and movable arms. The flaggers take workers out of harm’s way. Emmerich said flagger systems tested in Wisconsin received positive reviews.
“One of the biggest hazards in the road industry is the flagger that is out there flagging traffic,” Emmerich said. “The most common roadway worker that is struck by traffic a lot of times is the flaggers because they have to work close to traffic and almost integrate with that traffic.”
Some technology yet to catch on
In-vehicle communication devices are another technology intended to keep workers and drivers safe. WisDOT implemented a communications system called the Wizard that broadcasts messages and alerts over CB radios.
“I think that has had varied effectiveness. The project where we tried it in Wisconsin it seems that it did not make a lot of difference in driver merging,” said Notbohm, referring to an Interstate 94 project west of Eau Claire last fall. “It’s reaching only truckers and not reaching the broader population.”
In-vehicle navigation systems can retrieve real-time traffic information regarding work zones, but those devices do not reach all drivers.
“We are not quite there yet,” Notbohm said. “Sometimes it is going to take a generation to make a leap like that in technology. A lot of it depends on what people grow up with in terms of using technology. It’s coming but it takes time.”