Rebalancing Java-Sumatra Logistics from Land-Based Thinking to Maritime Efficiency

By RJ Lino, former president director of PT Pelindo II.

Every year, approximately four million heavy trucks-each above ten tons-cross the Sunda Strait between Merak and Bakauheni. This is not merely a busy domestic corridor; it is very likely one of the busiest roll-on/roll-off crossings in the world. The scale alone should position it as a strategic national asset. Yet, paradoxically, it also reveals one of the most  fundamental misalignments in Indonesia’s logistics system. 

At first glance, everything appears to function. Trucks move continuously from Java to Sumatra. Ferries operate around the clock. Goods arrive. The system gives the impression of efficiency, even resilience. But this impression, upon closer examination, is misleading. What we are observing is not an optimized logistics architecture, but a system that continues to operate effectively despite being designed against its own geographical logic. 

Indonesia is not a continental nation. It is an archipelago. Its natural infrastructure is not land, but sea. And yet, much of its logistics system today remains shaped by a continental mindset, one that assumes efficiency is best achieved through roads, continuous trucking, and uninterrupted land movement. In such a framework, the sea is not perceived as infrastructure, but as a gap to be crossed as quickly as possible. Ports become endpoints rather than nodes, and vessels become extensions of the road rather than carriers of cargo. 

Nowhere is this more evident than in the Java–Sumatra corridor. The ferry system  between Merak and Bakauheni does not transform logistics into a maritime flow. It merely allows trucks to continue their journey across water, as if the sea itself were an inconvenience. What emerges is, in effect, a highway that stretches from Java into  Sumatra, partly on asphalt, partly floating on the sea. It is an impressive system in terms of scale, but deeply inefficient in terms of design. 

This inefficiency is not immediately visible because it is masked by structural distortions.  The most significant of these is fuel subsidy. Diesel for heavy trucks is priced far below its economic cost, making long-distance trucking appear artificially competitive. As a result,  decisions that should have been driven by efficiency are instead driven by price signals that do not reflect reality. The system continues to expand along this distorted logic,  reinforcing itself year after year. 

When quantified, the magnitude of this distortion becomes clear. The four million trucks operating annually in this corridor consume approximately 1.07 billion liters of diesel,  equivalent to around 900,000 tons. With a subsidy gap of roughly Rp 6,000 per liter, this translates into a fiscal burden of approximately Rp 6.4 trillion per year. This figure alone is significant, but it represents only part of the cost. The same system consumes between  800,000 and one million truck tires annually, representing an additional Rp 4 to 5 trillion (US$235M–$294M) in mechanical wear. At the same time, it generates approximately 2.9 million tons of CO  emissions each year, contributing to environmental degradation that remains largely unaccounted for in economic terms. 

These costs are not static. With traffic growing at approximately five percent annually, the system is on a trajectory that will amplify these burdens. Within five years, the number of trucks will exceed five million per year, fuel consumption will surpass 1.3 billion liters, and the subsidy burden will approach Rp 8 trillion (US$470.6 million) annually. At that point, the congestion along the Jakarta–Merak corridor will reach a level where the construction of a second toll road becomes unavoidable. But such an expansion would not represent progress. It would merely be a response to a system that has been allowed to scale without being corrected. 

A critical question therefore arises: are we solving logistics challenges, or are we continuously expanding the infrastructure required to sustain inefficiency? 

It is often argued that trucking remains the most economical mode of transport, even under these conditions. However, when examined more closely, this assumption does not fully hold. A comparison between the current truck-based system and a direct maritime alternative, such as a roll-on/roll-off (RoRo) route between Jakarta and Palembang, reveals a different picture. Under current conditions, with subsidized fuel, trucking costs range between Rp 375,000 (US$21.88) and Rp 450,000 (US$26.47) per ton. When fuel is priced at its economic value,  this increases to between Rp 450,000 (US$26.47) and Rp 550,000 (US$32.25) per ton. By contrast, a maritime-based system combining RoRo transport with short-haul trucking at both ends operates within a range of approximately Rp 325,000 (US$19.12) to Rp 425,000 (US$25) per ton. 

This comparison is significant. It demonstrates that maritime transport is already competitive, even when competing against a system supported by substantial subsidies.  Once those distortions are removed, maritime logistics does not merely compete, it becomes structurally more efficient. The implication is clear: the dominance of trucking in this corridor is not the result of superior efficiency, but of policy-induced imbalance. 

The alternative is not to eliminate trucking, but to reposition it within a more balanced system. Instead of using trucks for long-haul transport across islands, they should be utilized for shorter distances, feeding cargo into a maritime network that carries goods over longer routes. This requires a shift in architecture, not just in operations. Direct maritime connections between Jakarta and key ports in Sumatra, such as Panjang,  Palembang, Jambi, Dumai, Bengkulu, Padang, and Kuala Tanjung, would fundamentally alter the flow of goods. In such a system, the sea becomes the primary corridor, and land transport becomes a supporting component. 

If even half of the current truck traffic were to shift to maritime routes, the impact would be immediate and substantial. Fuel consumption would be reduced by approximately  535 million liters per year, equivalent to around 450,000 tons of diesel. This would translate into a reduction in subsidy burden of approximately Rp 3.2 trillion (US$188.2 million) annually. Tire consumption would decline by hundreds of thousands of units, saving an additional Rp 2  to 2.5 trillion (around US$118 million - $147 million) per year. Emissions would decrease by approximately 1.4 million tons of CO  annually. At the same time, congestion along the Jakarta–Merak corridor would ease,  extending the lifespan of existing infrastructure and delaying the need for costly expansion. 

Yet, perhaps the most important benefit lies beyond these measurable savings. It lies in reliability. Logistics systems are often evaluated based on cost per kilometer or speed of movement, but in reality, their effectiveness is determined by predictability. Truck-based systems are inherently variable, subject to congestion, delays, and operational uncertainty. Maritime systems, when properly structured, offer scheduled departures,  stable transit times, and scalable capacity. As reliability improves, inventory requirements decline, supply chains stabilize, and the broader economic system becomes more efficient.

This is, ultimately, a question of perspective. The current system is not the result of poor execution, but of an inherited way of thinking, one that is rooted in continental logic.  Indonesia’s challenge is not simply to improve its logistics, but to realign it with its own geography. This does not require abandoning what has been built, but rather rebalancing it. 

The Java–Sumatra corridor provides a clear and compelling starting point. It is a system of global scale, operating at high intensity, and carrying strategic importance. But it is also a system that reflects a deeper imbalance, one where the sea is still treated as a boundary, rather than as the backbone of connectivity. 

In an archipelagic nation, this distinction is fundamental, not philosophical. Efficiency depends on treating the sea as part of the system itself—an active corridor of movement and connection. When it is integrated as infrastructure, the geography that once seemed to divide instead becomes the foundation of how the nation moves.

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