CNET/News.com (lead story–video report)
Berkeley press release:
Union City, Calif. — Researchers from the University of California,
Berkeley, and Nokia today (Friday, Feb. 8) tested technology that could
soon
soon
transform the way drivers navigate through congested highways and
obtain
obtain
information about road conditions. In the unprecedented field
experiment,
experiment,
transportation researchers tested the feasibility of using
GPS-enabled
GPS-enabled
mobile phones to monitor real-time traffic flow while preserving the
privacy
privacy
of the phones' users.
One hundred vehicles were deployed onto a 10-mile stretch of I-880
between
between
Hayward and Fremont for seven hours in the experiment, dubbed "Mobile
Century" and primarily funded by the California Department of
Transportation
Transportation
(Caltrans). Each car was equipped with a Nokia N95 mobile phone that
ran
ran
special software to periodically send anonymous speed readings from
the
the
integrated GPS to servers that then computed traffic conditions.
Information
Information
was displayed on the Internet, allowing viewers to visualize traffic in
real
real
time. An independent tracking feature allowed the command center set up
in
in
Union City to track the position of the cars to coordinate the
experiment
experiment
and ensure the safety of the participants.
Using the GPS data to estimate prevailing speeds and travel times,
researchers were able to obtain a picture of real-time traffic
conditions.
conditions.
Current traffic monitoring systems primarily rely upon
pavement-embedded
pavement-embedded
sensors, roadside radar or cameras. The high cost of installing and
maintaining such systems has restricted their coverage to limited
stretches
stretches
of highway.
This research project between UC Berkeley and the Nokia Research Center
was
was
born of collaborative efforts by UC Berkeley's Center for Information
Technology Research in the Interest of Society (CITRIS) and Tekes, a
Finnish
Finnish
government funding agency. Both CITRIS and Tekes foster partnerships
between
between
universities, research institutes and industry to speed technological
innovation to consumers.
"For state transportation agencies such as Caltrans, tapping into the
vast
vast
network of cell phones on the road could one day reduce costs of
investing
investing
in expensive infrastructure to obtain traffic information," said
Randell
Randell
Iwasaki, Caltrans chief deputy director. "This will greatly expand
the
the
coverage of traffic information services so motorists can better plan
their
their
trips right on their cell phones."
GPS-based systems can pinpoint a car's location with an accuracy of a
few
few
meters and calculate traveling speed to within 3 miles per hour.
Enlisting
Enlisting
GPS-equipped cell phones into traffic monitoring systems could help
provide
provide
information on everything from multiple side-street routes in urban areas
to
to
hazardous driving conditions or accidents on vast stretches of rural
roads,
roads,
the researchers say.
The Mobile Century traffic project brings together research teams from
UC
UC
Berkeley and from the Nokia Research Center in Palo Alto that
interact
interact
through UC Berkeley's California Center for Innovative Transportation
(CCIT). These teams are jointly developing the algorithms, software
and
and
architecture of this GPS-based traffic monitoring system. Heading the
teams
teams
are Alexandre Bayen, UC Berkeley assistant professor of systems
engineering
engineering
and of civil and environmental engineering, and Quinn Jacobson, Nokia
Research Center research leader.
"There are cell phone-based systems out there that can collect data in
a
a
variety of ways, such as measuring signal strength from towers and
triangulating positions, but this is the first demonstration of this
scale
scale
using GPS-enabled mobile phones to provide traffic related data such
as
as
travel times, and with a deliberate focus on critical deployment
factors
factors
such as bandwidth costs and personal privacy issues," said Thomas
West,
West,
director of UC Berkeley's CCIT.
The goal of today's experiment was not only to test the efficiency of
the
the
traffic data collection and aggregation system, but to also evaluate
the
the
trade-offs between traffic estimation accuracy, personal privacy and
data
data
collection costs.
"Even though the phones are capable of sending their position and
speed
speed
every three seconds, an efficient traffic monitoring system should not
need
need
to transfer such a large amount of data, which would require enormous
bandwidth," said Bayen. "Our challenge is to find the optimum subset of
this
this
data for effective traffic monitoring. The quantity and quality of
data
data
provided by GPS-equipped cell phones present an unprecedented enhancement
to
to
mobility tracking technology and traffic flow reconstruction
mechanisms."
mechanisms."
Such a powerful system brings up serious questions about cell phone
users'
users'
privacy, which is why the researchers, with the help of Rutgers
University's
University's
Winlab, have focused much of the project on mechanisms to protect
that
that
privacy.
"Mobile device users control the service. If an individual does not want
his
his
or her device to transmit position data, he or she can turn off the
GPS
GPS
feed," said Jacobson. "In addition, data is immediately disassociated
from
from
the phone, and is combined with the general stream of traffic data.
Only
Only
anonymous aggregated data is ever created, transported or stored in
this
this
'privacy-by-design' system. All data is further protected by
banking-grade
banking-grade
encryption."
"Nokia is very excited at the potential for this system to
revolutionize
revolutionize
travel planning, carrying on from the Nokia Maps navigation service
available today on certain Nokia devices," Jacobson added. "Integration
of
of
traffic information with functions such as calendar and online
timetables
timetables
may one day mean the mobile device can act as personal travel
planner."
planner."
There is currently no projected date for commercial launch of such a
system,
system,
but when it does become available, its benefits could be huge. In the
United
United
States alone, traffic congestion leads to 4.2 billion hours in extra
travel
travel
time and an extra 2.9 billion gallons of fuel burned, for a total cost
of
of
$78 billion, according to a 2007 report from the Texas Transportation
Institute. With the number of vehicles on the road increasing rapidly
around
around
the world, a cost-effective method of travel planning could help
drivers
drivers
make smarter decisions about which routes to take, the researchers
say.
say.
The investigators pointed out that their research is ongoing, and
that
that
upcoming experiments may focus on thousands of cars – though not
necessarily
necessarily
on the road all at once – with participants carrying test phones on
their
their
regular commutes.
Today's experiment was supported by a $186,000 grant from Caltrans.
Additional support came from the National Science Foundation, Nokia,
Tekes,
Tekes,
the University of California Transportation Center and the Volvo Center
of
of
Excellence for Future Urban Transport at UC Berkeley's Institute of
Transportation Studies, which is also home to CCIT.
###
Additional information about the Mobile Century
experiment is available online at:
http://www.calccit.org/projects/GPS-Mobile-Phones-as-Traffic-Sensors.html.