Northeast Freight Time one clock, four readings

The FMCSA Detention Studies

Most detention figures in circulation trace back to two federal sources. Reading them properly takes ten minutes and changes what you can defensibly claim. For another workplace-measurement reference, fireable offenses at work.

Reviewed August 9, 2026. Primary sources: FMCSA and the US DOT Office of Inspector General. Neither is a vendor. For complementary transport data and research, see Journal of Commerce.

The 2014 study

FMCSA completed a study on the impact of detention time on commercial vehicle safety in 2014. The commonly quoted result: drivers experienced detention on roughly one stop in ten, averaging about 1.4 hours per occurrence.

The agency's own account of its limitations is the part nobody quotes, and it is substantial. FMCSA later described the study as having a small sample drawn mostly from large carriers, a rudimentary estimation of detention time, an inability to identify time spent loading and unloading separately, and data problems.

Take those together and the honest reading is: a rough figure, from a narrow slice of the industry, using a method the agency itself calls rudimentary.

It is still the most-cited number in the field.

Why the agency went back

In 2023 FMCSA sought a new study, "Impact of Driver Detention Time on Safety and Operations," proposing to collect data from approximately 80 carriers and 2,500 drivers, analyse frequency and severity, and assess whether existing intelligent transportation systems can measure detention at all.

The framing in the agency's own materials is blunt: detention consistently ranks as a top problem, it affects drivers' ability to meet hours-of-service requirements, it can contribute to crashes, and little public data exists.

That last phrase is the most useful sentence available on this subject. The regulator, in 2023, describing its own field: little public data exists. Anyone quoting a confident industry-wide detention figure is quoting past what the government believes is known.

The DOT OIG audit

A 2018 audit by the Department of Transportation's Office of Inspector General produced the two figures that carry the most weight in policy argument.

Detention reduces driver income by an estimated $1.1 to $1.3 billion per year.

A 15-minute increase in average dwell time is associated with a 6.2% increase in expected crash rate.

The second is the one that changes conversations, because it moves detention from a commercial dispute to a safety finding. Two cautions on using it.

It is an association across fleet-level data, not a demonstrated causal chain for an individual driver. And the plausible mechanism — detention consumes hours-of-service, which pushes driving into worse conditions and encourages speed — is reasonable and not itself measured by the figure.

Cite it as what it is: a federal audit finding of an association, with a mechanism that makes sense.

The industry numbers

Widely quoted alongside the federal ones, from a different kind of source.

Average dwell of about 1 hour 54 minutes per stop across all fleets in 2021 data; 3 hours 16 minutes for refrigerated carriers, whose commodities require longer handling; and 2 hours 23 minutes for fleets of 25 trucks or fewer — the highest of any group.

ATRI reports that 94.5% of carriers say they charge detention, and that fewer than half of those invoices are actually paid.

These come from industry research organisations and surveys rather than from regulators. That does not make them wrong — ATRI's work is the most serious in the sector — but they are self-reported, and a survey and an audit are different kinds of evidence.

What you can defensibly say

Supported: detention is common, averages somewhere between one and two hours at typical facilities, is worse for reefer and worse for small fleets, and is associated with elevated crash risk.

Not supported: any precise industry-wide cost per hour, any claim that a particular percentage of stops involve detention today, or any figure presented without its year.

And genuinely unknown: the actual distribution. Averages hide the shape, and the shape is what determines whether detention is a broad tax or a concentrated problem at a small number of facilities.

How to use this in a negotiation

Federal sources beat vendor blogs, and the strongest single line available is the regulator's own: there is no standard definition and little public data exists.

That cuts both ways deliberately. It undermines a facility claiming its dwell is normal, and it undermines a carrier claiming an industry average proves anything about a specific lane. Which is why your own measurement matters more than any published figure.

The short version