As geopolitical disruption continues to affect global supply chains, bunker prices have risen sharply, placing renewed cost pressure on ocean carriers. Public commentary already points to the scale of that impact, with one major global carrier recently stating that the Middle East crisis is adding US$40–50 million per week to operating costs, largely driven by bunker price.
When bunker costs rise this quickly, carriers have only a limited number of levers available to respond. Some are commercial, including emergency surcharges and pricing adjustments. Others are operational, such as network changes, capacity management and vessel speed optimisation. Among the most immediate is slow steaming: reducing sailing speed to lower fuel consumption and help contain operating costs.
WTG analysis of carriers’ published average transit times over the next eight weeks suggests that this may already be emerging in carrier operating patterns. Compared with a rolling eight-week baseline, forward transit times are beginning to rise across major trade lanes. The clearest signal is on Asia–Europe services, where published average transit times are trending above recent norms.
On its own, an increase in transit time does not necessarily indicate slow steaming. Voyage duration can also be influenced by a range of factors, including port congestion, schedule recovery, blank sailings, network redesign and adverse weather. But when forward transit times begin to extend as bunker prices rise and carriers publicly highlight fuel-driven cost pressure, the pattern warrants close attention.
For supply chain teams, that matters because the impact of higher fuel costs does not stop at surcharges. It can also flow through into longer lead times, weaker schedule reliability and greater variability in planning assumptions. For shippers, the impact is not only financial; it can also make planning materially more complex.
Transit time is more than an operational metric. It affects how businesses plan inventory, manage customer commitments, set safety stock levels and control working capital. Even modest changes in average sailing duration can have outsized consequences when supply chains are already under pressure and volatility remains high.
That is why this trend matters now.
During periods of disruption, market attention typically centres on freight rates and surcharges. Those are highly visible: carriers announce them and shippers see the impact quickly. Transit-time changes are different. They are rarely announced directly and are more often embedded in published sailing schedules and service data. That makes them easier to overlook, even when they may be signalling a meaningful shift in carrier operating patterns.
From a shipper’s perspective, this creates a different kind of risk. Unlike surcharges, which are clearly communicated, slower networks can emerge more quietly through schedule revisions. That makes them harder to identify early unless shippers are actively monitoring schedule data for changes in carrier operating patterns.
This is where forward-looking data becomes especially valuable. Instead of waiting for weaker service performance to appear in historical reporting, shippers and freight forwarders need solutions that can indicate where future risk is rising and help them respond before that risk translates into disruption. Carrier schedule data and forward transit-time trends can provide some of those early signals.
The current signal does not suggest a universal shift across all trades, nor does it point to slow steaming as the only explanation. But it does indicate that fuel-driven operating pressure may already be influencing service patterns on key lanes. For businesses exposed to long-haul ocean freight, particularly on Asia–Europe corridors, that possibility should now form part of supply chain risk planning.
The practical implication is straightforward: shippers should watch more than freight rates. In the weeks ahead, one of the clearest indicators may be the relationship between bunker prices, changes in carrier behaviour, and forward transit-time changes by trade lane. If bunker prices remain elevated, the first meaningful market impact may not simply be higher costs. It may be slower networks.
For shippers and freight forwarders, the ability to detect those shifts early will matter increasingly. In a market where disruption can move faster than traditional reporting cycles, forward-looking visibility into emerging transit-time risk will become more important to planning and execution.
Further information:
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