Must-know: All the basic
road markings in PH and what each one means
Niky
Tamayo
Reading road markings is an important skill for new drivers, yet it's one
that even veteran drivers seem to lack.
Perhaps it's because our road
signage and markings seem to be in a perpetual state of flux, and even the
authorities painting them often seem puzzled by where they should actually go.
When you find lane markings
directing you into a telephone pole planted in the middle of the road, it's
probably best to use your better judgment instead.
Even so, it can't hurt to familiarize yourself with
these basic lane markings, because they might save your life.
1.Solid white shoulder line. This denotes
the edge of the roadway. Any asphalt or concrete surface beyond this line
should not be used during the normal operation of your vehicle.
2.Diagonal white lines. An area
filled with diagonal white lines and bordered by solid white lines is not
considered part of the roadway, and vehicles are expected to stay off unless
there is an emergency. These areas are often used to ease the flow of traffic
where roads diverge or intersect.
3.Broken white center line or lane divider. This denotes the center of a two-lane road, or marks the division
between lanes on multi-lane roads. It is a reminder to stay in your lane.
Straddling the line is illegal and punishable under the law. As the line is
“broken,” however, this means it is legal to cross it when overtaking or
changing lanes. Bear in mind that vehicles continuing in a straight line within
their lane automatically have right of way, so wait for your turn.
4.Solid white center line. This is
often used to divide traffic on a two-way multi-lane road. As this is a solid
line, you are discouraged from overtaking over it unless the way is absolutely
clear.
5.Solid white double center line. You
are forbidden from overtaking over this line, but you may make left turns over
it, provided the way is clear. Remember, however, that oncoming traffic still
automatically has right of way.
6.Solid yellow double center line. As we
noted a while back, this line
indicates that it is unsafe to
overtake at any time. It is often found around blind curves or in areas where
fast-moving two-way traffic meets on an undivided road.
7.Mixed center line/solid yellow with broken yellow or white line. This indicates that only one side can overtake--the side
with the broken line. This is often found entering curves where the view is
obstructed coming from one direction, but is clear from the opposite side.
8.Solid white lane divider. These are
often found near intersections, and are reminders to stay in lane. As a
practice, if you're turning at an intersection, it's best to get into the
turning lane 50m before the intersection, while the lane divider is still
broken.
9.Directional arrows. When combined with solid white lane dividers, they indicate which directions you are allowed
to go within a lane. If the arrow points forward only, you cannot make a turn
from that lane. If it points forward and to the side, you can either go
straight or turn. If it points only to the side, you must turn within that
lane. Ignoring these arrows might just get you a ticket, or worse, get you into
an accident.
10.Broken blue lane divider. This
indicates the motorbike lane along major thoroughfares. The broken line indicates
that you can move into and out of it, but the lane is preferentially for
motorbikes.
11.Solid yellow lane divider. This
indicates the bus lane on EDSA, but can also be used to indicate bicycle lanes
in some areas. Bicycle lanes may also be indicated by solid white lines on the
side of the road.
12.Broken yellow lane divider. This
indicates areas where you can merge into the bus lane in preparation for
turning off EDSA.
13.Mixed double lane divider/solid yellow with broken yellow or white line. This indicates that traffic on the solid yellow side cannot
cross lanes, while traffic on the other side may do so if the way is clear.
This is often used where smaller arteries merge into main roads or where feeder
roads merge onto the highway.
14.Rumble strips. These tightly spaced horizontal white lines not only give your car's suspension a bit of a workout,
they also indicate hazards ahead, such as dangerous curves or merging traffic.
15.Solid white horizontal line. This indicates
where you must stop at a stoplight or stop sign.
16.Zebra crossing. This indicates a
pedestrian crossing zone. Stopping over this at a red light is a traffic
violation, so make sure to pay attention to those light timers!
17.The
yellow box. This box indicates the part of the
intersection that must--by law--be kept open at all times. Even if you have a
green light, if the traffic is stopped on the other side ahead, it's best to
wait until there's enough space for you to clear the yellow box. Even in the
absence of a light, the yellow box must be kept clear.
Memorize these road markings
and you will be more law-abiding than 90% of drivers on Philippine roads,
guaranteed.
And hopefully safer as well.
Niky
Tamayo
Writer
Niky's first automotive article was a 5,000-word
essay on Life, the Universe and the Suzuki Alto. The published version was
slightly more readable. Niky joined Top Gear Philippines on the promise of someday getting to braid James
May's hair. He's still waiting.
Why can't we
convert salt water into drinking water?
BY NICHOLAS GERBIS
It seems strange that water
should be such a scarce resource when our planet is drenched in 326 million
trillion gallons of the stuff.
But it turns out that less
than one-half of 1 percent of it is drinkable.
Out of the rest, 98 percent
is oceanic salt water and 1.5 percent remains locked up in icecaps and
glaciers.
The
stark irony of Samuel Coleridge's immortal line "Water, water, everywhere / Nor any drop to drink" is
manifest each year in coastal disasters around the world, like Hurricane
Katrina, the 2004 Indonesian tsunami and the 2010 Haiti earthquake, as people
within sight of entire oceans are threatened with dehydration.
Between droughts, natural
disasters and the large-scale redistribution of moisture threatened by climate
change, the need for new sources of potable water grows with each passing day.
Each year, the global
population swells by another 85 million people, but worldwide demand for
freshwater increases at twice the rate of population growth, doubling every 20
years or so.
Throughout the world, our
most vital resource is under stress from pollution, dam construction, wetland
and riparian ecosystem destruction, and depletion of groundwater aquifers, with
poor and marginalized populations getting the worst of it.
So why can't we convert
seawater into drinking water?
Actually, we can and we do.
In fact, people have been
making seawater drinkable at least as far back as the ancient Greeks.
But when taken to the scale
of cities, states and nations, purifying seawater has historically proven
prohibitively expensive, especially when compared to tapping regional and local
sources of freshwater.
However, as advancing
technology continues to drive costs down and freshwater continues to grow
scarcer and more expensive, more cities are looking to seawater conversion as a
way to meet this vital demand.
Read on to find out how and
where seawater is being converted into drinking water today, including how
desalination is bolstering disaster relief in Haiti.
How and where is desalination used today?
Desalination
has come a long way in the 2,400 years or so since people boiled salt water and
collected the steam in sponges.
Yet, the most widely used
method is still based on the same principle: distillation.
Essentially, distillation
artificially mimics what occurs in nature: Heated water evaporates to become
water vapor, leaving salts and impurities behind, and then condenses as it
cools to fall as freshwater (aka rain).
Distillation plants refine
and speed up this process by applying artificial heating and cooling and by
evaporating water under lower air and vapor pressure, which significantly
reduces its boiling point.
This method requires a great
deal of energy, however, so distillation plants are often located alongside
power plants, where waste heat is available to bring the water up to a volatile
temperature.
Another method, reverse osmosis (RO) desalination, uses pressure to force water
through filters, straining out other substances at the molecular level.
Developed in the 1960s, the
process became feasible on a commercial scale in the 1970s, ultimately
replacing distillation as the method used in most new desalination facilities,
in part because it requires less energy.
Besides removing salt, both
methods remove virtually every mineral and most biological or organic chemical
compounds, producing water that is safe to drink, far exceeding federal and
state drinking water standards.
So
how widespread is desalination?
Specific
figures are elusive, as new plants are constantly being added and little data
exists concerning plants that have shut down.
It's
also tricky to separate counts of distillation versus RO plants.
However,
a good ballpark figure is 8,000 RO seawater desalination plants globally
producing a total of about 10 billion gallons (37,854,117 cubic meters) of
drinking water each day, with older distillation plants still outnumbering RO.
The
largest users of desalination globally in terms of volume capacity are (in
descending order) Saudi Arabia, United Arab Emirates, United States, Spain,
Kuwait and Japan.
Desalination
provides 70 percent of drinking water in Saudi Arabia.
Within
the United States, Florida, California, Texas and Virginia are the largest
users, and the country as a whole has the capacity to desalinate more than 1.4
billion gallons (5.6 million cubic meters) of water per day.
To
put that in perspective, that equates to less than 0.01 percent of municipal
and industrial water use nationwide.
Cruise
ships, submarines and ships of war have been using desalination for decades.
One
impressive example, the aircraft carrier U.S.S. Carl Vinson, can make some
400,000 gallons (1,514 cubic meters) of its own freshwater every day, half of
which is excess water that at press time is being used to aid disaster relief
in Haiti.
As
much as desalination has increased over the years, it is still just a drop in
the bucket.
In
this next section, we'll look at what's holding us back from a full-on sea
change in freshwater supply.
The Cost of Desalination
There's little doubt that the world needs
more drinking water.
It's
also abundantly clear that the need will keep pace with mounting population
growth and the pressures brought about by global climate change.
In
the United States alone, experts agree that water demand already exceeds
supply, projecting that 36 states will confront shortfalls within the next
three years.
Within
15 years, almost 2 billion people globally will live in areas confronting water
scarcity, and, according to most model scenarios, such shortfalls will only
worsen under climate change.
Indeed,
the availability and distribution of water is widely discussed as a likely
determining factor in future global stability.
So, what is holding
us back from diving in headfirst? Until recently, purifying seawater cost
roughly five to 10 times as much as drawing freshwater from more traditional
sources.
RO
filters have come a long way, however, and desalination today costs only half
of what it did 10 to 15 years ago.
Consequently,
transportation, energy and environmental costs have now replaced technology as
the primary impediments to large-scale desalination.
Energy consumption
accounts for as much as one-third of the total cost of desalinated water,
making even coastal plants expensive to operate.
Inland
states must also grapple with the sizeable expense of transporting seawater
inland.
They
can opt to use local brackish (salty) water sources, instead, but then they
face a different problem: how to dispose of the byproduct, a concentrated salt
solution that coastal sites have the luxury of pumping back into the ocean (a
practice that remains controversial in environmental circles).
Zero
Liquid Discharge (ZLD) plants are one way out, but they drive up the energy
costs of what is already an energy-intensive process.
Is
desalination cost-effective? The answer probably depends on where you live.
Given
the high costs of freshwater importation and reclamation, desalinating seawater
is an increasingly attractive option for water-stressed areas.
The
potential for desalination is limited mostly by social, political,
environmental and economic considerations, which vary from place to place.
Any
way you look at it, the rising tide of desalination seems likely to remain a
growing part of our water portfolio for years to come.