Section D This section consists of one passage
followed by a summary. Read the passage carefully and complete the summary below
by choosing no more than two words from the passage for each blank. Remember to
write the answers on the answer sheet. Questions 61 to 65 are based on the following
passage. Sitting in stationary traffic is, at best, a
Zen experience. Drivers mired in a jam learn to cede control to the powers that
be, becoming at one with the universe as they breathe in the mind-numbing fumes
all around. At worst, it is an on-going battle for sanity. But now, according to
several groups of researchers in America and Germany, there is something that
drivers can do to take back control over the roads. Get adaptive cruise control.
And, of course, use it. Adaptive cruise control (ACC) , as its
name suggests, is a modified version of traditional cruise control. It employs
radar to monitor the road ahead of a vehicle, automatically adjusting that
vehicle’s speed to maintain a safe distance from the one in front. This is safer
than manual driving because it reduces the system’s reaction time from nearly a
second (human) to practically instantaneous (machine) , thus helping to
forestall shunts. But ACC may have a useful side-effect, arising from the fact
that another effect of slow human reaction times is to produce traffic jams on
apparently open roads. Such jams start when a car slows suddenly
to allow, for example, another vehicle to enter the traffic stream. Slow
reaction times mean that instead of responding smoothly, the drivers behind such
a vehicle often end up slamming on the brakes. That slamming propagates
backwards, and before long the traffic is at a standstill. So it makes sense
that ACC would reduce not only collisions, but also congestion. What is
unexpected is how few vehicles need to have it operating for all to benefit. As
Craig Davis of the University of Michigan reports in Physical Review E, only 20%
of cars need to employ ACC in order to prevent completely those jams that are
caused by a slow lead car on a high-speed, single-lane road. According to Dr.
Davis’s computer model, even a rate of use of ACC as low as 13% can improve the
flow of traffic significantly. ACC is not a panacea. Dr. Davis
got less promising results for more complex road conditions, particularly those
near junctions. And a similar model built by Boris Kerner, a researcher for
Daimlet Chrysler, in Stuttgart, Germany, indicates that in certain bottleneck
conditions, ACC may even cause extra congestion. These disappointing results
can, however, be ameliorated by shortening the "headway" in ACC-equipped
vehicles, according to Martin Treiber of the Dresden University of Technology,
also in Germany. Headway is the gap, measured in seconds, that a
driver puts between himself and the car ahead. Since ACC reacts more quickly
than a human, people who have it fitted can afford to allow less
headway. Summary : Stationary
traffic can drive people mad. However, according to American and German
researchers, adaptive cruise control (ACC) can help drivers take (61)
. ACC adapts a car’s speed to keep a safe distance from the one ahead
by using radar to monitor the road ahead. ACC is safer than manual driving
because it significantly reduces the system’s (62) , and
collisions and congestion in addition. According to Dr. Davis’ computer
model, if (63) of cars use ACC, the flow of traffic can be
improved significantly. However, ACC should not be seen as a panacea. In
(64) conditions, it may even cause extra jams, according to
a computer model. But this situation can be improved by reducing (65)
in ACC-equipped vehicles.