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Go With The Flow
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Early warnings
expected to improve traffic woes.
By Kevin Kipp
If there’s no cure for dumb drivers, (and no shortage) at least
the Missouri Department of Transportation has a way to make traffic
a little smarter.
It’s ITS, the Intelligent Transportation System, a collection of
ways to improve traffic flow.
Tom Ryan, MoDOT’s assistant district engineer, says ITS is a national
program, whose local incarnation is Gateway Guide. MoDOT will put
up roughly 60 percent of the $200 million scheduled for investment
in the St. Louis region over the next 10 or 15 years.
Ryan says the ITS priorities are clear. “A 1994 study determined
that 70 percent of vehicle miles are on freeways, so that’s where
it makes sense to focus your effort. We try to keep everybody flowing
at 55 or 60 mile per hour.”
MoDOT’s website suggests that when freeway traffic is slower, it
is caused by “incidents” more than a shortfall in capacity. Among
the site’s bullet-point statistics: “During peak hours, one minute
of lane blockage can cause about 20 minutes of traffic congestion;
a vehicle on the shoulder reduces capacity of the closest lane by
20 percent; approximately 60 percent of congestion is caused by
incidents.”
“An incident,” Ryan clarifies, “can be anything from an accident,
to someone running out of gas, to debris falling off the back of
a vehicle—anything that impacts travelers’ movement.
“The frustrating part is that in peak hours an incident can have
an impact for four or five hours,” he says. “So the quicker we can
find an incident, the quicker we get it cleared, the less impact
it has on traffic.”
He says the tools of detection include radar, closed circuit cameras,
and under-pavement metal detectors (not pressure sensors!), “inserted
from the side of the road.”
(All three are considered “non-intrusive” technologies: “On Interstate
270,” he says, “we’re approaching 200,000 cars a day. We don’t think
it makes sense to stop traffic to make it flow better.”)
The detection tools in turn will interconnect with a traffic operations
center—an impressive command and control facility (think NASA) at
Interstate 64 and Woods Mill Road—as well as dynamic message boards
located strategically throughout the area.
Tom Darnold, market principal at Jacobs Engineering Group, says
Jacobs Facilities, a subsidiary, provided the engineering support
for the traffic ops center’s HVAC, electrical and telecommunications.
Sverdrup Civil, another subsidiary of Jacobs Engineering Group,
sited the cameras, radar detectors and message boards, and also
designed their electric and telecommunications connections to the
traffic management center.
Darnold says the telecom connections a fiber optic backbone along
more than 180 miles of St. Louis region freeways is a public-private
partnership between MoDOT and telecom contractor DTI. The company
got to install their bundled fibers; MoDOT got a portion of the
bundle for its use.
“The camera registers a change in color in the lanes where it’s
focused,” he says. “It allows us to compare the flow of cars. If
it’s the same as yesterday, we can conclude there’s not a problem.”
On the other hand, “vastly fewer cars tells us there’s probably
a problem and where,” Darnold continues. “Then [from the comfort
of a MoDOT traffic operations center] we can zoom in on where we
think the incident occurred, and confirm what has happened or not.
Then the operator will get a set of instructions on the screen detailing
a set of actions”: call emergency services, alert the media, change
a dynamic message board, “so that motorists can reroute around incidents.”
“We’re planning 13 signs initially,” Ryan says, estimating that
St. Louis Metro would eventually warrant 50 or 60. “For instance,
the signs coming into St. Louis along Interstate 70 will tell you
what you’re likely to encounter ahead. They’ll be at decision points,
two miles before interchanges like 40/64, 370, 270, 170.” Darnold
says, “Oftentimes people don’t value the quickest travel time, but
rather the most reliable route. This information helps them decide
what is the most reliable route. That peace of mind is worth a lot
to people.”
Still, Darnold is aware that no single ITS component nor even the
collective ITS is the “save-all or end-all. But it helps whenever
you can squeeze a little efficiency out of the system. One percent
here, two percent there...pretty soon you have a substantially improved
transportation system.”
Additional ITS components are: traffic radio signs that flash alerts
that they’re broadcasting pertinent information, routing toll-free
cellular calls to the traffic operations center or highway patrol,
improved highway mile markers to pinpoint incidents, Motorist Assist
vehicles, direct media tie-ins for traffic and weather information,
and ramp metering and control.
MoDOT plans to invest in some arterial traffic flow as well, Ryan
says: “We’re doing signal interconnects on major arterials, like
Lindbergh, Manchester and Olive. Once you hit a green light, we
try to time succeeding lights so that a platoon of cars will get
through them. But in peak times, some of the roads are so overloaded
you can’t always get it to work.”
No matter how smart you are.
Kevin Kipp runs Bubble Communications, a creative services and
community relations firm in St. Charles. |
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