The Hidden Costs of Port Congestion: Why Shippers Pay More in Detention and Demurrage

U.S. ports are the backbone of international trade. When they're running smoothly, cargo flows, trucks turn quickly, and supply chains stay on schedule. But when congestion sets in, everything slows down. Containers stack up in terminal yards, truckers sit in hours-long queues, and vessel schedules fall further behind each day.

For shippers, the real pain isn't just delayed cargo. It's the detention and demurrage (D&D) charges that start piling up — often for delays completely outside their control.

In this article, we'll look at how port congestion drives detention and demurrage costs higher, why U.S. ports are particularly vulnerable, and what shippers can do to reduce their exposure when things back up.

How Port Congestion Triggers D&D Fees

Port congestion happens when cargo volumes overwhelm available infrastructure — yard space, terminal labor, trucking capacity, or even chassis supply. When any of these break down, containers sit longer than planned, either inside the terminal or once they're picked up.

That's where detention and demurrage come into play:

• Demurrage applies when containers remain in the terminal beyond the allotted free time.
• Detention kicks in when containers are out on the street too long before empty equipment is returned.

Even the most efficient supply chain can get caught by congestion. These fees aren't about individual performance — they're the result of system-wide bottlenecks that ripple across ports and terminals.

When ports clog up, containers sit 2–3x longer. Longer dwell time is the root cause of both demurrage and detention

Why Congestion Drives Demurrage Higher

When terminals are congested, demurrage risk rises quickly. Common issues include:

• Longer dwell times: Import containers aren't available for pickup, burning through free time.
• Truck gate delays: Drayage may be scheduled, but trucks can wait hours — or fail to get in at all.
• Customs slowdowns: When CBP resources are stretched, clearance delays become more common.

Each additional day at the terminal can mean $150–$300 per container in demurrage. With escalating daily charges, costs can multiply fast — especially when containers are inaccessible through no fault of the shipper.

Demurrage escalates fast. What starts as a small delay becomes a major cost within days.

Why Detention Costs Spike During Congestion

Congestion doesn't end once a container leaves the terminal. On the detention side, shippers often face:

• Chassis shortages: Containers sit on scarce chassis while warehouses wait for capacity.
• Warehouse backups: Full yards and labor shortages slow unloading.
• Empty return restrictions: Terminals may limit or suspend empty returns, leaving importers stuck with equipment they can't return.

The result is a frustrating cycle: detention charges accrue even when shippers are ready to return containers — but have nowhere to take them.

Detention costs rise sharply when shippers can't return equipment — even when they're ready to.

Real-World Congestion at U.S. Ports

Recent history offers plenty of examples of how congestion translates into higher D&D exposure:

• Los Angeles / Long Beach (2020–2022): Pandemic-era import surges led to record vessel queues. Many containers sat inaccessible for days or weeks, generating massive demurrage bills.
• New York / New Jersey (2022): Truckers faced multi-hour gate waits, while empty return appointments were scarce, driving detention costs higher.
• Savannah (2021–2023): Rapid volume growth strained yard capacity. Exporters were especially impacted when vessels rolled or cut-off times shifted unexpectedly.

Each case highlights the same lesson: port-specific congestion quickly turns into shipper-paid fees.

The Hidden Costs Beyond the Invoice

Detention and demurrage charges are only part of the story. Congestion also creates downstream impacts, including:

• Supply chain disruptions that affect production and retail availability
• Cash-flow pressure from sudden five-figure D&D invoices
• Customer service issues caused by missed delivery windows
• Operational strain as teams spend hours tracking, disputing, and reconciling charges

In other words, congestion doesn't just slow freight — it consumes time, money, and attention across your organization.

Detention and demurrage are just the visible costs — congestion impacts the entire business.

How Shippers Can Reduce Their Exposure

While congestion can't always be avoided, shippers can take steps to limit the financial damage:

• Stay current on free-time rules: Carriers and terminals frequently adjust tariffs during peak periods.
• Secure drayage early: Early planning reduces dwell time and missed appointments.
• Monitor port conditions: Congestion reports and vessel backlogs can help with smarter scheduling.
• Negotiate where possible: High-volume shippers may be able to secure extended free time or fee caps.
• Use technology for visibility: Centralized tracking of D&D rules across carriers and terminals gives shippers leverage and foresight.

How D2 Helps

When ports clog up, detention and demurrage rules change quickly — and tracking those changes manually is nearly impossible.

D2 helps shippers stay ahead by:

• Tracking D&D tariffs across U.S. carriers, ports, and terminals
• Alerting users to rule changes before costs escalate
• Helping analyze charges and identify opportunities to reduce exposure

With the right visibility, congestion becomes a challenge you can manage — not a surprise that wrecks your budget.

Final Thoughts

Port congestion is an unavoidable part of global trade. But the hidden costs of detention and demurrage don't have to catch shippers off guard. By understanding how congestion drives fees, staying on top of changing rules, and using the right tools, shippers can control costs and keep freight moving — even when ports are backed up.

Detention and demurrage may be the symptom. With the right strategy, you can address the cause — and protect your bottom line.