Changing climate

Winter concept vehicles give an edge to snow fighters in Wisconsin

GPS Article March 21, 2002
Printer-friendly version

If only Wisconsin’s economic lights worked as well as
the new high-intensity discharge lights on its snowplows, the state might be
able to forecast the funding climate.

The state is facing a revenue shortfall because of general economic conditions two years into a three-year trial of winter maintenance concept vehicles. The program is similar to programs in Iowa, Minnesota and Michigan. Three of the high-tech trucks hit the Wisconsin roads in winter 1999-2000; four more joined the program in 2000-01; one more was added this winter.

The trouble is that this winter has been so mild the state has not had much of a chance to test the equipment in severe weather. A major
storm passed through the area in early February and dropped 4 in. of snow on
Madison, but the bulk of the flakes stayed to the south.

“We want to make sure that we have been able to use
these trucks in various weather conditions as far as light snow, heavy snow,
wet snow, dry snow, frost, black ice,” Thomas Martinelli, P.E., winter
operations engineer for the Wisconsin Department of Transportation, told Roads
& Bridges. “I was hoping that we could pull things to an end at the
end of this winter, but because we’ve had a very relatively mild winter
here in Wisconsin, I think we’re probably going to continue to test and
evaluate through one more winter season before we feel comfortable in bringing
it to a close.”

The state is funding the program, but the counties are
executing it. The state contracts with the counties to perform road
maintenance, and the trucks are owned by the counties. The state is paying
eight to put high-tech concept equipment on one of the county’s
replacement trucks. The county pays the cost of the truck it would have bought
anyway; the state pays up to $60,000 for the concept equipment. The state pays
an hourly rate to the county for the time the trucks spend maintaining the
state’s roads.

“Currently, we have not increased the hourly
rate,” Martinelli said. “As part of the project, the counties are
collecting data on what is the cost to operate and maintain each of those
pieces of concept equipment. We will eventually probably establish hourly rates
for the major concept equipment components.”

There are 72 county highway departments in Wisconsin and 711
winter patrol sections, with one truck each. The counties not participating in
the concept vehicle testing hope to learn from the eight that are.

Putting the pieces together

One concept device the truck operators in Wisconsin really
like is the high-intensity discharge (HID) lighting. There has been some
controversy about these lights. Some drivers have complained that HID lights on
cars blind oncoming traffic, but on the winter maintenance trucks the lights
are mounted on top of the cab, and the complaints have been minimal.

“It really cuts through snow clouds and through
fog,” Martinelli commented.

Another piece of concept equipment that makes it easier for
the truck driver to see the road is a front-plow snow shield, an attachment to
the plow that directs the snow down instead of letting it fly up into the
windshield of the truck.

“By adding the snow shields, we’ve pretty much
prevented almost all the snow from coming back up on the windshield,”
said Martinelli, and avoided the cost of frequently replacing cracked
windshields and worn-out windshield wipers.

An airfoil attached to the top of the truck at the back
prevents blowing snow from coming over the top and sticking to the back of the
truck.

Heated lenses keep snow from caking on the truck lights,
make the truck more visible to other vehicles and should reduce rear-end
collisions from other vehicles.

Light-emitting diodes (LEDs) are used for some of the lights
on the back of the truck and on the ends of the wing plow on the side of the
truck. LED lighting is brighter and stands up to harsh weather better,
Martinelli said. The lights on the wing plows also may help prevent a motorist
from crashing into the plow while trying to pass the truck on the right.

Heated rear-view mirrors make it easier for the driver to
see the area around the truck.

Another aid to the driver’s vision is a camera mounted
on the back of the truck. A monitor in the cab can tell the driver whether he
is about to back into a mailbox. It also can tell him if the salt spreader is
clogged and not actually spreading salt.

Dual spinners on the concept vehicles allow the operator the
flexibility to spread salt down the middle of the road from the driving lane or
the passing lane. The salt then gets spread out from the middle of the road by
traffic and the slope of the road.

A zero-velocity salt-spreading unit seemed like a good idea.
The device was intended to automatically adjust the salt spreaders to cast the
salt in such a way that the speed of the salt negates the speed of the truck
and the salt drops on the road with no horizontal speed. When the truck is
moving faster, the spinner throws the salt out faster. The salt would stick to
the pavement better with such a device, and less of it would be lost by
bouncing off the pavement.

Unfortunately, the zero-velocity salt-spreading mechanism
did not work as intended. It is still under development.

Another device tied to the speed of the truck is a control
for dispensing liquid and solid anti-icing and deicing materials.

“As the truck slows down, the spinner slows
down,” explained Martinelli, “so he’s applying a constant
application rate of salt.” With the currently used manual control, the
operator might forget to turn off the spreader at a stop sign and then drive
away leaving a pile of wasted salt.

Another way to make solid salt stick to the pavement better
is to prewet it with a liquid chemical. Prewetting also promotes the
snow-melting process to start faster. The winter concept vehicles have on-board
prewetting units that spray brine on the salt as it goes on the road. Martinelli
said the on-board system is more effective than spraying brine on the salt in
the truck as it leaves the garage.

A concept that did not meet with enthusiasm is the global
positioning system tracking of trucks in the field. Martinelli observed:
“I don’t think our people have bought into the value of that
technology yet.” The operators worry that it is going to be used for
eavesdropping. The managers see the potential for gathering real-time
operational data such as material use and plow use.

A real-time weather display in the cab ran into problems
communicating with the garage.

The operators like the joystick for controlling up to six
functions such as raising and lowering the plow blades.

One operator commented that he had to take his eyes off the
road too much to operate the truck controls. Martinelli said the issue was
under consideration.

“We’re trying to simplify things for [the
driver], but I’m not sure if we’ve been able to accomplish that or
not. If you saw a picture of one of these cabs and all the technology
that’s been added, it definitely needs more work in downsizing.”

 

Forecast: cloudy

Martinelli is part of the WisDOT committee that will decide
which concept components should be made a standard part of the snow fighting
arsenal. The committee has not yet made a decision, but some of the counties
are already incorporating some of the equipment. The most popular are the front
snowplow shield, the rear airfoil, the HID lighting, the joystick controllers
and the LED lighting on the wings.

One challenge the state faces is determining how much any of
these concept components improve snow fighting performance. The engineering
department at the University of Wisconsin is working on a cost analysis,
including comparing patrol sections served by concept vehicles with patrol
sections served by standard trucks.

Because of budgetary anxieties, the state has already
directed employees to travel less and have fewer face-to-face meetings. The
American Association of State Highway & Transportation Officials reported
in its AASHTO Journal that Wisconsin faced a $1.1 billion shortfall in general
purposes revenue in 2002 and about the same in 2003. WisDOT was reportedly
supposed to transfer $21 million in transportation dollars to the
general-purpose fund to make up part of the shortfall. Decreased transportation
funding raises the specter of reduced levels of service.

The concept equipment may save enough money to offset its
cost, but the future is uncertain.

“I don’t know what the future is going to bring,
but the climate has definitely changed from when we first started this project
to now,” said Martinelli. “We’re looking at things a lot
differently because of the budget situation the state is in.”

About the author: 
Overlay Init