This is one of the biggest annual migrations of people on earth.
Millions of Indonesians have started leaving urban centres for their hometowns and villages,
ahead of the muslim holiday season of Eid.
Every year this piece of infrastructure becomes the backbone of something called Mudik.
A giant homecoming for people all across Indonesia travelling back for Eid al-Fitr.
Special services are laid on for trains, ferries and planes. There’s even live coverage of the
traffic as hundreds of thousands of people return to their hometowns and villages in Sumatra.
It’s a major test for Indonesia’s roads and bridges, and … it can be a bit of a struggle.
Until now.
This is all thanks to one of the biggest infrastructure projects in Southeast Asia,
a network of new routes across Indonesia that includes this: The Trans Sumatera Toll Road,
which when it’s completed will span the entire length of the island.
Weaving through the dense rainforest and tropical conditions of Indonesia’s
second largest island, building this massive road is far from easy – but
it’s already having a big impact on Sumatra, and in more ways than one.
Sumatra is roughly the size of California, and produces nearly a quarter of the country’s GDP.
Despite that, getting around is not exactly straight forward.
The island has a small and largely disconnected rail system, and travelling
by road for any significant distance means you’re in for a bit of a bumpy ride.
That’s why in 2015 the Indonesian government announced the construction
of the imaginatively named Trans Sumatra Toll Road.
So the initial plan to build the Trans Sumatra Toll Road is to reduce the
logistic cost and also reduce the travel time. The government
also wants to boost the economic growth of the island of course.
The plan was huge. The road would stretch for nearly 3,000km from
the port of Bakauheni in the south to the city of Banda Aceh in the north.
The main highway would provide a link from the south to the north of the island
and roads would branch off to connect cities along the more remote western coast
as well as key towns and ports to the east.
It wasn’t cheap – an eye watering USD $37BN was earmarked to complete the project
over a nearly decade long construction period.
The contract was given to Hutama Karya and work began in 2015.
Now if you wanted to imagine the ideal conditions to build a road in,
it would probably look something like this:
First you’d take a nice long flat stretch of ground and make sure there weren’t any
rivers or other roads in the way which you’d have to build bridges over.
Ground conditions are pretty important. You’ll need strong,
dry, well compacted soil which can stand up well under the weight of all your traffic.
Water is a big no-no as it can seep into the ground and weaken the foundations,
and you’ll need to avoid any extremes of temperature and humidity
which can also stress and degrade the quality of the road.
Finally to make your life easier you’ll want to make sure the land you’re building on
is clear and obstacle free so you don’t have to waste any time clearing a path.
So, what’s it like in Sumatra?
Huge parts of Sumatra are covered in dense rainforest which throw up
pretty much every engineering challenge possible.
This 28km stretch of road between Pematangsiantar and Serbelawan shows the challenges faced.
This key stretch of the road links the major city of Medan to the industrial port of Kuala Tanjung
and the nearby tourist hotspot of Parapat City.
The path for the road lay through dense, remote rainforest,
and even just surveying it was never going to be easy.
Instead of relying on traditional techniques, conducted manually on the ground, the construction
team turned to LIDAR technology. That enabled them to create an accurate picture of the road
which could then be integrated into infrastructure engineering software provided by Bentley Systems.
LIDAR is similar to radar and sonar in that it emits a pulse towards an
object and measures the time for the pulse to return to calculate distance.
With nearly half a million of these measurements made every second the data that generates
can create an incredible accurate picture of the ground.
LIDAR surveys are usually conducted from aeroplanes, but that was quickly ruled
out as an expensive and impractical option for the Trans-Sumatra Road.
Instead the team used a drone, mapping the ground with a tolerance of 25cm throughout the route.
Aside from accuracy, LIDAR also has the advantage
of using laser pulses rather than sound or radio waves to do its job.
Just like rays of light passing through a forest, the light from the laser beam is able
to pass through soft vegetation. The strength of the light returned is measured to give a
three dimensional picture of the survey area, allowing the team to map out the dense jungle.
The result was a survey for this stretch of the road that ran to just 28 days:
nearly 100 days quicker than planned.
But it’s more than just above ground conditions the team had to work through.
Being in a humid rainforest and all, the ground beneath the construction site is soft.
Soil samples showed areas of soft soil and clay 13 metres deep.
You don’t need to be ann engineer to work out that’s not the ideal conditions to build
a road on that hundreds of thousands of people are going to be driving on.
It will be crossed heavily by, say, large trucks. And then it will create some cracks
when the soil are not solid or not giving a reinforcement.
To add stability to the road a fabric membrane, known as a geotextile was laid under the six
metre embankment. This helped water filtration and reduced the stress on the soft underlying earth.
The geotextile basically consists of the non-woven, polyester and polypropylene.
It's like a layer that can be thrown on the top of the soil to prevent the soil displacement.
It has the ability to separate and reinforce the with the soil itself.
Managing a project which includes everything from soil samples to LIDAR mapping needs a
powerful set of tools to help make sense of the vast amount of data.
For this, the team at Hutama Karya turned to Bentley whose suite of programmes
have made them an industry leader in infrastructure engineering software.
Bentley’s software is able to combine data from different sources, like LIDAR scans,
to create a complete digital model of the project,
enabling the project team to visualise the job in a variety of ways.
Bentley LumenRT was used to create a visualisation of the road which was
pretty central in identifying problems and displaying them in visual ways.
In this case the planned route clashed with an existing road, but a visualisation
was used to quickly identify the need for higher bridge clearance.
For a project reliant on state funding,
advanced technological solutions like this are essential to keep costs down.
We are very happy to use all of these resources and how we can bring the valuable advantage to
elevate the digital transformation of the project, so we can ensure that this toll road will be
in the best quality that can be used by all of the people for the next maybe 40 or 60 years.
When the road is completed it will have major benefits for Sumatra’s economy.
As well as a booming tourist industry, the island boasts enormous mineral wealth,
which once earned it the nickname the Island of Gold.
Sumatra has huge deposits of oil, silver and coal
and is a major producer of tea, coffee, rice and corn.
With journey times due to be cut in half by the road and logistics costs reduced by
30 percent, these export industries will all benefit massively from the project.
But who in turn will benefit from this economic development?
I don't doubt that it will support economic development as it
supports connectivity and stuff. But there is a worry that it will only be enjoyed by not many
Existing roads set to be bypassed by the new toll route provide a
valuable source of income for many of the island’s poorer citizens.
Now, suggestions have been made to try and replicate their businesses along the new highway.
Local communities will have their, you know,
small, medium businesses that have been through more than ten or 15 years being like having
stalls in the road where a lot of people would come and stop by for their lunch,
their meals, or even just have their cup of coffee when they're on a road trip break.
There should be some sort of allocation where existing businesses can open
on the toll road. Where they plan to make a lot of rest areas, will there be opportunities for
existing communities to open there and if they do will there be subsidies for them as well
As well as the human element, there’s also concern for Sumatra’s rich ecosystem,
which hosts many critically endangered animals.
This branch road connecting the main highway to the city of Padang cuts across the border
of the Kerenci Seblat National Park, the biggest of its kind on the island
and one of the most important tiger conservation habitats in the world.
In terms of tigers, it's actually one of the the key species of Sumatra that still
remains very much in the wild. By fragmenting their roaming area through
the road, cutting, you know, there will be increase of human wildlife
conflict activities where the tigers in itself will roam into community areas.
In a place as verdant and wild as Sumatra economic development will
almost always be at odds with the natural environment and there are no easy answers.
Indonesia’s economic growth has helped reduce absolute poverty
levels from over 70 percent in the 1980s to less than 10 percent today.
For that economic growth to continue across Sumatra it will need reliable,
modern infrastructure like the Trans Sumatra Toll Road – a key part of developing tourism,
shipping and industry across the island.
And it’s important to note that it doesn't always have to come at a cost to wildlife.
We also conserve the natural habitat of elephants. So we develop also like a
crossing for the elephants and another section of that. So we also consider
the sustainability of the animals around these animals.
I think my personal view is that I'd like to be as helpful
as possible, because it does. I do hope that I think as long as there will be opportunities for.
Civil society organisations those communities to also take part later on to
have. You know, have our suggestions be considered and be implemented.
Just over 650km of the road is currently operational,
so there’s still some way to go if it’s to meet its planned completion date of 2024.
Once fully open it’ll have a profound effect on the island and give Sumatra
the key piece of modern infrastructure that it needs if it wants to grow further.
While the wider implications of this remain to be seen,
anyone taking part in Mudik will definitely have an easier ride.
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