America's bridges are struggling. More than a third of
the nation's bridges are in need of repair and over 43,000 are in
poor condition and classified as structurally deficient. A
structurally deficient bridge is one that requires significant
maintenance to remain in service. It is often posted with
weight limits, but is considered safe to use. Each day, about 167
million trips are taken in the US across structurally deficient
bridges.
The state of bridges in the US is not good and we're losing the
battle, if you will.
America used to have the best roads, bridges and airports on
earth and now, our infrastructure is ranked 13th in
the world.
Hours ahead of President Biden scheduled visit to Pittsburgh in
January 2022. to discuss infrastructure, one of the
city's more than 440 bridges collapsed. Ten people were
injured, including first responders.
I think what we found is that we deferred maintenance for a long
time and then all of a sudden, we're at the point where, oh, we
have this big backlog of maintenance that we have and we
don't really have the funding to catch up at this point.
Another bridge collapsed in Washington State in 2013 and in
Minneapolis in 2007. And while most of the country's structures
were designed for a service life of about 50 years, the average
age of bridges in the US is 44 years. Older bridges with fewer
lanes and restricted access can add to congestion impacting
commerce and the response time of emergency services.
Because we are working on the busiest bridge in the world
we're over the Hudson River 200 feet above the water at the
roadway level. The towers are 600 feet above the water. It
proposes a tremendous amount of difficulty. But
innovations in bridge building, new building materials, as well
as additional funding is showing signs of some modest improvement
for the nation's bridge inventory. In January 2022,
President Biden announced his administration would distribute
$27 billion over the next five years to fix or rebuild
thousands of the nation's bridges. The current estimate to
repair all bridges in the US is $125 billion. So why are so many
of the nation's bridges in a state of disrepair and what
steps are being taken to fix them?
The US had more than 618,000 bridges in 2020, almost 44% were
in good condition, 50.9% were in fair condition and 5.2% were in
poor condition. Those bridges are also facing a midlife
crisis. As of 2022 to 42% of bridges in the US are at least
50 years old, an increase from 39% in 2016. More than 10% of
the country's highway bridges are 80 years or older.
In the 1950s, 1960s, we built a lot of roads and highways and
bridges in the United States. Most of them were designed for
traffic loads that were 30 years into the future. So that would
have taken us capacity wise to like the 1980s or 1990s. The
population in this country has continued to grow, and
commercial traffic has continued to grow. So we've put increasing
wear and tear on the bridges in this country.
California home to more than 25,000 bridges that handled 673
million crossings each day has about 1,500 structurally
deficient bridges. The 8.4 mile long San Francisco Oakland Bay
Bridge opened to the public in 1936 at a cost of $77 million.
But in 1989, an earthquake hit the Bay Area, causing a section
of the structure to collapse, killing one person. Another 42
people were killed when a one mile section of the nearby
Cypress viaduct in Oakland also collapsed.
The bridge was designed of course in the 1930s when our
understanding of earthquakes and our understanding of how steel
and concrete react to those types of forces was not as
advanced as it was come 60s, the 80s and 2000.
The Bay Bridge was quickly repaired, but a decision was
later taken to rebuild the entire eastern span.
One of the very first designs that was proposed for the Bay
Bridge was a very plain vanilla quote unquote, type of structure
and the Bay Area objected to that uninspired aesthetic, let
me put it that way. So there was a halt to the design process and
a rethinking and we ended up with of course a more striking
type of structure. But even that had its problems because the
redesign envisioned a 700 foot tower that was going to lean on
a 15 degree angle. And that led to extremely complicated
technical issues and expensive issues.
Skyrocketing costs and design issues plagued the project.
According to Ibbs the revised project came in over budget and
had to be redesigned yet again, safety issues were another
factor. Prior to the opening, a survey found 32 of the more than
2,300 steel rods used to withstand earthquakes were
damaged.
All told it took almost two decades to really rebuild the
project and somewhere north of $5 billion to rebuild this
really important structure that was crucial to the Bay Area
commerce and Bay Area travel.
The new section the Bay bridge opened in 2013 five times over
budget, and six years behind schedule, at a cost of $6.4
billion. While most bridges in the US are owned by either a
local or state agency, about 2,200 are privately owned.
Linking Detroit Michigan with Windsor, Canada, the privately
owned Ambassador Bridge opened in 1929. The bridge accounts for
about a quarter of goods traded between the two countries.
Canada is one of the US's largest trading partners with
more than $600 billion in goods traded in 2019. But congestion
and concerns related to pollution, as well as
bottlenecks due to increase security have led stakeholders
to call for a new river crossing.
We go back 100 years when the Ambassador was first built, the
amount of traffic going across there was quite small compared
to today. I don't think anybody at that time could predict the
integration of the two countries in their economies.
In 2020, there were over 2.2 million truck crossings annually
on the Ambassador Bridge.
That seems to be a classical problem with many, many bridges
in the US not just this private one is you build them today to
last 50 years, you build them based on a traffic count of
today and with some projection. But then people grow. People
travel across and maybe migrate from one state to the other,
traffic volume increased significantly. Now there is not
enough lanes that are always heavier traffic than design
loads. And that would create some of the deteriorations that
we see on bridges.
In 2018, construction began on the Gordie Howe International
Bridge located just a few miles away.
So you probably see there a lot of the steel and they're going
to be pouring concrete all around this location here.
One of the reasons why the government of Canada went down
this path of building this new bridge is to ensure that there
is always this connection, and that there's a redundancy in the
area to make sure that even if the Ambassador Bridge, for
instance, had to close to do renovations to enhance his life,
we don't want to lose that capability to put goods back and
forth between the two countries.
In addition to the cost building a bridge on an international
border has its own set of challenges, including
coordinating with local, state and federal authorities as well
as Border Services in two countries. So how to you
build a bridge over water when the next support you have for it
is 1000 feet away, half a mile away. It's quite the engineering
feat and the construction feat that we're going through to
actually construct this infrastructure project, it is
something to see.
Construction of the bridge is being done using a balanced
cantilever method. This involves building to 720 foot towers on
both sides of the Detroit River and then building the bridge
deck piece by piece outwards until the two cantilevers meet
in the middle, costing an estimated $4.5 billion the
Gordie Howe International Bridge. A six lane 1.5 mile long
cable stay design is set to open in 2024. The bridges designed
for a service life of 125 years. While 77% of all US bridges are
located on rural highways, 73% of all bridge traffic takes
place on urban bridges. The George Washington Bridge is one
of the world's busiest bridges. In its first full year of
operations in 1932, more than 5.5 million vehicles crossed
between New York and New Jersey. By 2019 the bridge was handling
more than 122 million vehicles annually. Those additional cars
and trucks have led to gridlock for commuters and truckers
making the bridge the top ranked US truck bottleneck, according
to 2019 data. Congestion on the nation's highways cost the
trucking industry more than $74 billion in 2019, the equivalent
of over 425,000 truck drivers sitting idle for an entire year.
The relentless traffic has also brought with a decades of wear
and tear on the 90 year old bridge whose to 604 foot towers,
along with their suspended structures contain more than
43,000 tons of steel.
This is probably one of the most vital links in the I-95 corridor
along the entire highway system. We pretty much connect
everything from down south to Florida all the way up through
New England. If you can't cross this bridge, New England gets
cut off.
In the mid 2010s. The bridges owner the Port Authority of New
York and New Jersey kicked off a decade's long construction
project in a bid to rehabilitate the structure. One key component
was to replace all the bridges 592 vertical suspender ropes,
which have been in place since it opened in 1931.
Here you have the cable bands that go around the main cable
and support the suspender ropes that go down to the bridge
structure below. So we would remove the existing suspended
rope, remove the cable band, take that off site, clean it up,
paint it, bring it back and reinstall it, and then reinstall
the new suspended rope.
Other projects include the installation of a
dehumidification system, replacement of the bridge's
sidewalks and the replacement of roadways leading to the bridges
bus station. The project is expected to cost about $1.9
billion. But are US bridges safe for travel? Yes, according to
one analyst. The role of evaluating bridge deficiencies
lies with the Federal Highway Administration that provides
guidelines for bridge inspections in States Department
of Transportation units, who are usually the arbitrator of
whether an overpass is safe for operation. In general, bridge
inspections occur every 12 to 24 months.
From an industry perspective, we want to find urgency. And one
way to find urgency is to say that, look, we have all these
poor bridges, this is a dire situation we need to but really
from the engineering and safety side of it that does not
necessarily match up with people are in danger right now. Because
our processes are working. Our safety factors are working, our
inspection is working. Our mitigation is working once we
find that there are issues with bridges.
And while the backlog of bridges in need of repair or replacement
is massive and the cost daunting innovations in bridge building,
along with new materials is allowing engineers to keep
structures in service for even longer.
You're seeing advances in terms of new materials of
construction, new concrete, new steel, new asphalt, you're
seeing advances in terms of the way in which we build bridges.
There are now programs that emphasize modularization and
pre-fabrication of components of bridges so that we can get in
and get out real quick with renovation of bridges.
The bridge was built in 1931 it's been here for 90 years it
is still functional and in a state of good repair. And the
work we're doing is to ensure that it lasts for another
century to come.