CONGESTION CURE
Peter Price, the council's transport
policy manager, said, "The Urban Traffic
Management Control system (UTMC) is a high-tech
system that links all the traffic lights in the
city. This is not actually in place yet, but if a
bus is approaching lights that are on green,
they'll stay on green until the bus goes through.
UTMC aims to keep traffic moving through
junctions." But the lights only stay green
for buses. |
GRIDLOCK
Shoppers and fans arriving for a
football match were stuck in queues because of
faulty traffic lights in Derby city centre.
Problems at one of the city's busiest junctions
led to long delays on a Saturday afternoon. The
lights at the Cockpit Island were faulty, causing
them to change too quickly, leading to severe
congestion. The problems saw many fans arrive
late for the Derby County v Plymouth Albion game
at Pride Park. They were also held up when
leaving the ground. Engineers hoped to have the
problem fixed by the Sunday morning. |
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TRAFFIC LIGHTS
The government is
facing a legal challenge from thousands of motorists
after the attorney-general admitted that they had been
wrongly penalised for jumping red lights. Drivers could
have three penalty points scrubbed from their licences
following the discovery of a legal loophole that has
existed for 16 years. The problem relates to motorists
who have been penalised by traffic cameras or policemen
for going through red lights at more than 300 level
crossings that have been created since 1990.
The crossings were signed off by the Health and Safety
Executive (HSE), but government lawyers have realised
that, according to current law, only the Department for
Transport (DfT) and its immediate agencies, such as the
Highways Agency, have the power to approve them. That
means that the 306 level crossings have, technically,
been erected illegally. Those drivers who have been fined
and had their licences endorsed with penalty points after
being caught jumping red lights at these crossings will
now be able to challenge these offences.
Both Lord Goldsmith, the attorney-general, and Ken
Macdonald QC, the director of public prosecutions, are
understood to have been consulted over the bungle.
We have got to assume that were talking about
thousands rather than hundreds of drivers, given the
number of level crossings involved, said a
Whitehall source. However, motorists who have been
prosecuted for more serious offences, such as dangerous
driving, at these crossings are unlikely to have their
cases quashed by the courts.
The loophole came to light as government lawyers pored
over the Road Safety Bill. The government, however, is
unlikely to disclose the location of these illegal rail
crossings until the Road Safety Bill has received royal
assent. A source said, We will try to make it as
difficult and as expensive as possible for anyone to
challenge us in the courts. Even though these drivers
might have been wrongly penalised due to a technicality,
we would use the moral argument that they were
potentially endangering lives by ignoring a red
light. (Source: Times Online, Oct/06)
Traffic
lights have been installed at the A38 Abbey Hill
roundabout at Little Eaton to ease congestion. The lights
cost £220,000 and will work on a part-time basis during
the afternoon between 3pm and 7pm. Motorists said the
new configuration is dangerous, with drivers from the
B6179 Alfreton Road making their own judgments about
whether or not it is safe to enter the flow of traffic.
Mike Taylor of Little Eaton, said, "I use the
roundabout a lot and the new lights are dangerous. You
take your life into your own hands if you're trying to
get on the roundabout from Alfreton Road. They either
need to change the timing of the lights or put lights at
the Alfreton Road junction."
A spokesman for road contractor AMScott, who installed
the lights, said he believed the installation of the
traffic lights has improved traffic on the roundabout
saying, "Instead of Alfreton Road drivers having to
wait for a random gap in the traffic on the roundabout
and then reacting very quickly to it, the gaps in traffic
are more regular and for longer. This means they can
enter the roundabout more safely then previously."
He added, "We've observed several vehicles leaving
Alfreton Road in one phase of the traffic signals.
Previously they would only have been able to exit one at
a time as gaps appeared. The scheme was designed to
reduce congestion on the major routes and we believe
we're already having significant improvements. However,
we'll have to wait until traffic patterns have settled to
get accurate figures and we're monitoring and adjusting
the signal phasing on a daily basis."
Ever felt that the traffic lights are
against you? Well, perhaps they are. Lights synchronized
to ease jams might be making matters worse, and rush-hour
traffic might flow better if lights were set at random.
Ideally, traffic lights are set so that each changes to
green just as a typical vehicle approaches from the
previous set of lights. But in dense traffic, queues
inevitably build up behind red lights, and it may be
impossible to ensure that each queue is fully cleared
during a single 'green-light' period. It then becomes
tricky to work out the best way of phasing the lights.
Urban planners trying to deal with dense traffic
currently have little more than a few empirical rules of
thumb to guide their decisions, say Ding-wei Huang and
Wei-neng Huang of Chung Yuan Christian University in
Chung-li, Taiwan.
They need a more systematic understanding of how
different modes of traffic-light synchronization affect
traffic flow, the duo argue. Huang and Huang used a
well-established computer model of traffic flow to
simulate a long, straight section of road that cars enter
and exit at a fixed traffic density. They positioned ten
traffic lights at regular intervals along the road -
these might, for example, be used to control the flow
where the road intersects with others. They found that
when traffic is light, cleverly synchronizing the lights
improves traffic flow, compared with no synchronization.
In fact, a good choice of delay times produced a flow
similar to that when there are no lights at all. Bad
timing, on the other hand, made the flow slower than if
lights were set at random.
But above a certain density of traffic, typical of
daytime flow in many cities, the choice of delay time
stopped making any difference to flow, the pair found. In
such traffic, lights turning green failed to clear the
queue that had developed in front of them. Vehicles
almost always had to wait at every set of lights - giving
journeys that all-too-familiar stop-go pattern. In very
heavy traffic, however, careful synchronization of the
lights can improve matters again, the pair discovered.
But here the traffic flow is much more sensitive to
random fluctuations in density, which can obliterate any
advantage gained by synchronization.
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