March 2026 - Decision Timing Brief

Savannah's 20-point VSSI drop is the month's largest single movement. On its face, it reads as a terminal-tier problem. The weekly DTB editions surfaced eight escalations at Garden City over the four weeks that make up this edition.

But the weekly signals lied by aggregation

When we look at which services those eight escalations sat on, seven of them trace to two ECNA rotations - MAEU TP6 and ONEY ECL. Remove those two services from the Savannah sample and the port's VSSI for the month is 58 - in line with last month, not a 20-point drop.

The implication is that the problem is not "Savannah volatility." It is "rotation-level instability on ECNA services that happen to call Savannah." A drayage team preparing for next month's volumes should not widen buffer at Garden City across the board. They should tighten monitoring on TP6 and ECL bookings specifically.

Oakland's four-point improvement is real

Oakland's movement is the inverse story. The improvement is distributed across services - no single rotation accounts for it. This is the signature of terminal-level change: possibly a gate operation shift, possibly a sailing rationalization. Worth monitoring for continuation in the next edition.

What this means for planning

Monthly diagnosis is where we learn whether weekly signals were pointing at the right thing. This month, they were pointing at a port when the cause was a rotation. Exporters working the affected services should plan accordingly. Exporters not on those services should not overreact to the headline Savannah number.