By Christopher MacKechnie. 
 
Subway construction can use two different methods: "cut and 
cover" and "deep bore". 
 
Older subway systems, such as those found in Toronto 
and New York, were built with a method known as "cut and 
cover". In "cut and cover" tunneling, the pavement of the street 
is removed, a hole for the subway and stations is dug, and then 
the street is restored. The "cut and cover" method is much 
cheaper than "deep bore" but the alignment is restricted to the 
street grid. "Cut and cover" also results in the stations that are 
much closer to the surface − as little as twenty feet ...A... the 
surface − which significantly reduces passenger access time. On 
the other hand, "cut and cover" results in serious disruption to 
traffic along the street for a significant amount of time; this 
disruption usually results in negative effects especially to store 
owners along the corridor. 
In "deep bore" tunneling, boring machines are inserted 
into a hole dug at a convenient spot along the proposed line, 
and then proceed through the earth little by little − up to eighty 
feet per day − until they have carved out space along the entire 
corridor. These boring machines are huge − the world's largest 
is fifty feet in diameter. Boring machines generally can excavate 
only in one fixed shape, which is generally circular. Because 
these machines do not have to follow the existing street grid, 
they allow for much greater flexibility in route design. In addition, 
there is no disruption to life along the surface − except at the 
machine insertion points, you would not even know a subway 
was being built. In exchange for these advantages are two major 
disadvantages. One is financial: "deep bore" construction costs 
significantly more than "cut and cover"; the underground stations 
alone can cost $150 million. Because of the large number of 
variables that make up the cost of subway construction, it is 
extremely difficult to quantify the cost differential between the 
two methods. The second is access: passenger access to "deep 
bore" stations is significantly more difficult than "cut and cover" 
stations, making the subway much less useful for relatively short 
trips.

By Benjamin Kabak. 
 
Over the last few months, we’ve heard a lot about the 
Metropolitan Transit Authority's efforts at securing its system. An 
ongoing lawsuit against Lockheed Martin has left the current 
state of subway security in disarray, and approximately half of 
the system’s 4300 cameras do not work properly. Had 
everything gone according to plan, by now, the entire subway 
system would have been outfitted with closed-circuit security 
cameras. 
Generally, this halting attempt at installing cameras 
doesn’t impact the public. We’ll ride the trains no matter what 
and hope for the best. But this weekend, two stories highlight 
both the benefits and limitations of subway security cameras. 
The first happened right here in New York when a stabbing on 
Sunday morning left two riders dead and the cops on the hunt 
for a killer. The NYPD’s efforts have been slowed by the lack of 
adequate security measures underground. 
MTA and New York City officials are aware of the 
system’s shortcomings − a patchwork of lifeless cameras, 
unequipped stations and problem-plagued wiring. Norman 
Seabrook, head of the MTA’s security committee, said to The 
Times, “Post-9/11, the terrorist bombings that just occurred in 
Moscow, the two murders that just occurred plus other incidents 
that continue to occur in the subway system, we ...B... any longer 
to ensure the safety of the public.” 
Yet, the Moscow bombings, despite Seabrook’s 
concern, highlight just how useless security cameras can be. 
During the Monday morning rush hour, two suicide bombers 
detonated explosives in the Moscow Metro. The bombers are 
suspected to be a part of some Northern Caucasus separatist 
groups, and the blasts raised fears through Russia and the rest 
of the world. 
In New York, the NYPD rushed to “activate” a security 
plan, Reuters reported on Monday. Police details flooded the 
subway system, and squads were dispatched to major transit 
hubs around the city. Although there was no suspected link 
between America’s enemies and the Russian attackers, the city 
wanted to maintain a strong security footing. It was, MTA 
spokesman Jeremy Soffin said to amNew York, a “precaution.” 
Yet, I wonder if this response is more an example of 
wishful thinking and the limitations we run up against in 
defending an open and porous subway system than it is of 
precaution. By dispatching police after the fact, it is as though 
security officials are trying to close the barn door after the horse 
escaped. As former NYPD commissioner Howard Safir said to 
Heather Haddon, “There are so many entrances, so many 
stations, so many people. It’s virtually impossible to guarantee 
that it won’t be vulnerable.”

Posted on Friday March 27th, 2009 by Jebediah Reed 
To give some sense of the pace of public works 
construction in China, the city of Guangzhou is planning to open 
83 miles of new subway lines by the end of next year. 
Meanwhile, New York − a city of about the same size − has 
been playing around with the 1.7-mile Second Avenue line for 
decades now. China also builds subways rather cheaply − $100 
million per mile versus $ 2.4 billion per mile in the Big Apple. 
Not surprisingly, projects there are more aggressive in all 
respects: there are 60 tunnel boring machines operating in 
Guangzhou, while only one is slated for the Second Avenue 
project; workers put in five 12-hour shifts a week (and if they 
don’t like it, they can go pound glacial till); and seizing property 
is a breeze.
An article in the Business section of today’s NY Times 
(Clash of Subways and Car Culture in Chinese Cities by Keith 
Bradsher) [VERB] a smart look at the forces at play as China 
goes on a transit infrastructure spending spree while it 
simultaneously becomes evermore sprawling and car-centric. 
Here’s one interesting passage, [CONJUNCTION] the 
story is worth reading in its entirety: 
Western mass transit experts applaud China for investing 
billions in systems that will put less stress on the environment 
and on cities. But they warn that other Chinese policies, like 
allowing real estate developers to build sprawling new suburbs, 
undermine the benefits of the mass transit boom. 
Mr. Chan Shao Zhang , a 67-year-old engineer in charge 
of the works in Guangzhou, defended Guangzhou’s combination 
of cars and subways, saying that the city built a subway line to a 
new Toyota assembly plant to help employees and suppliers 
reach it. 
Subways have been most competitive in cities like New 
York that have high prices for parking, and tolls for bridges and 
tunnels, discouraging car use. Few Chinese cities have been 
willing to follow suit, other than Shanghai, which charges a fee of 
several thousand dollars for each license plate. 
The cost and physical limitations of subways have 
discouraged most cities from building new ones. For instance, 
only Tokyo has a subway system that carries more people than 
its buses. The buses are cheaper and able to serve far more 
streets but move more slowly, pollute more and contribute to 
traffic congestion. 
China has reason to worry. It surpassed the United 
States in total vehicle sales for the first time in January, although 
the United States remained slightly ahead in car sales. But in 
February, China overtook the United States in both, in part 
because the global downturn has hurt auto sales much more in 
the United States than in China. 
There are many countervaling forces X . China has 
passed its own stimulus package and the government is eager 
to put people to work, create economic activity, and build 
modern infrastructure. The Guangzhou project is part of major 
national transit buildout. But the nation’s cities are also sprawling 
beasts, and in that sense, more suited to cars than trains. Not 
shockingly, many Chinese prefer the former.

Questões de Elementos gramaticais