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SCOOT: The traffic lights that count pedestrians- CNN

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In the one-sided battle between
pedestrians and the automobile, the first shot
was fired in London in 1896 when 44-year-old
Bridget Driscoll became what is believed to be
the first pedestrian victim of a petrol-driven car.

image

Struck down by an automobile doing just 4mph
during a demonstration at Crystal Palace, the
grim sequence of events was so unfamiliar that
one witness riding in the car told the inquest
she felt a “peculiar sensation” as the car
swerved to avoid Mrs Driscoll.
At the time, the coroner at the inquest
expressed the hope that an incident of this type
“would never happen again.”
Fast forward 118 years and more than 270,000
pedestrians are killed on the world’s roads every
year.
Striking a balance between the rights of the
pedestrian and the car driver was once the
preserve of the traffic cop — a human being that
could judge traffic flows, calibrate changes and
react to circumstances as they occur.
But as traffic volumes increased and
the task became automated with
traffic lights, the frustrations all too
familiar to pedestrians — lights that
seem never to show the “green man”
— are now tolerated as a normal part
of urban life.
London, however, is set to trial a new
system that aims to use the latest
technology to regain the fluid
responses of the traffic cop.
Called Pedestrian SCOOT (Split Cycle Offset Optimization Technique), it is
the first of its kind in the world and
uses state-of-the-art video cameras
to detect how many pedestrians are
waiting at crossings.
When the cameras count a critical
mass of pedestrians, the technology
transmits data that keeps the “walk”
sign lit for longer to allow more
people to cross the road.
Similarly, when fewer people are waiting to
cross the road, the traffic is given a longer set of
green lights.
The SCOOT system already regulates London’s
traffic flows and has been credited with cutting
delays by 12% in the capital. It is in use at 3,000
junctions in the British capital, with a further
1,500 earmarked for SCOOT upgrades by 2018.
The Pedestrian SCOOT system, however, would
be the first time the technology has been used
as pedestrian pinch points in the capital.
“Our SCOOT system has been used around the
world for many years use to optimize and
coordinate the traffic signal junctions and we’ve
done that currently and historically for vehicles,”
explained Mark Cracknell, team leader of the
Technology Delivery Group at Transport for
London.
“We have inductive loops in the road
that detect vehicles, do clever
analysis of the traffic patterns and
then coordinate the junctions to try
to make the progress through the
city as smooth as possible.”
Currently pedestrians at many
crossings in London get a standard six seconds
to get onto the road — known as the “green
man” time — before countdown technology takes
over telling pedestrians how long they have left
to get across the street.
What SCOOT technology aims to do is
dynamically change that “green man” time.
“If there’s only a few people waiting we’ll just
go for the standard six seconds to cross, but if
we’ve got 100 people waiting to cross we can
increment that up to the appropriate time.
“What we’re avoiding is the scenario where we
don’t have enough time to get everybody on the
crossing and then pedestrians have to wait for
another cycle of the traffic signals to get across.”
Cracknell said the system would have the most
value where the pedestrian traffic is variable,
for instance outside a school or a tube station.
“During the day there might be a low flow and
you don’t want to be fixed with a high crossing
time when there’s no one there,” he said.
“There are technologies out there that can
detect whether a pedestrian is waiting, but the
technology we use actually quantifies and counts
the number of people.
“We’re not aware that this is in use anywhere
else in the world.”
At the heart of the technology is a stereoscopic
camera that allows the sensors to detect and
count crowds of people in three dimensions.
“They’re vision-based systems, the
idea being traditional vision systems
just have a single camera and there
are a number of inherent flaws with
that — things like shadows, puddles
and changing light conditions can
cause problems.
“The stereoscopic camera allows us to get a
sense of depth — discount the puddles and the
shadows — and just get a picture of the people
standing there.”
Despite this it’s not all one-way traffic.
Pedestrians that press the button on a set of
lights and then change their minds and walk
away are another challenge to the free flow of
traffic.
Transport for London is trialing new technology
that would detect when a pedestrian has
changed their mind and strolled off or crossed
the road before the “green man” signal.
“This is what we call ‘call cancel’ technology and
we’re trialing it at different locations in London
— it’s the combination of both SCOOT and ‘call
cancel’ which we are looking at,” said Cracknell.
Ultimately, however, developing technology that
brings back the function of the human traffic
cop is the Holy Grail for Transport for London.
“We’re trying to be more intelligent with what
we’re doing. Rather than just tweaking the splits
of the vehicles, we will be catering for
everybody,” Cracknell said.

By Peter Shadbolt for CNN.

Credits: CNN

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