(NewsNation) — Before truck drivers can hit the road to deliver their goods, those goods need to be loaded onto their rig. But the amount of time it takes to load that freight varies widely, and it can often take hours.

Excessive time spent waiting at distribution facilities is known in the trucking business as “detention,” and it’s one of the most frustrating parts of being a truck driver.

Traditionally, the trucking industry defines detention as any time spent waiting to load or unload goods that is longer than two hours. So if a driver waits three hours to be unloaded, an hour of that would be considered detention.

Most drivers, including third-generation trucker Chris Eme, are paid by the mile, which means time spent waiting is money lost.

“If the truck is not rolling, you are not getting paid for the time you are sitting at the receivers,” Eme said.

Some truck carriers do charge facilities for detention time but that pay can be hard to get and rarely covers the entire cost of the driver’s lost time.

A 2018 report from the Department of Transportation’s inspector general’s office found detention time costs for-hire truck drivers between $1.1 to $1.3 billion a year. That reduces the average drivers’ annual earnings between $1,281 and $1,534 each year.

And research suggests female drivers may be waiting longer than their male counterparts.

In 2019, an analysis by the American Transportation Research Institute found women were 83% more likely than men to be detained for six hours or longer.

Why are women waiting longer?

In part, it could be due to the fact that a higher percentage of women drove refrigerated trailers than men, which experienced longer delays than other vehicle types the report found.

But the report revealed something else — it wasn’t outright sexism at loading docks delaying women but likely behavioral differences between male and female drivers.

Male drivers, the report found, were more likely to check in and express more “consternation” when stuck at a loading dock. That impatience and demand for action could lead to faster turnaround times.

It’s a finding that industry trade groups, including the Women In Trucking Association, are determined to address.

“They (women) are not going in and pounding on the desk and saying, ‘Get me out of here,'” said Ellen Voie, the founder and CEO of the Women in Trucking Association. “We’re trying to get them to be a little bit more assertive and say, ‘You need to go in and be like those guys.'”

Detention time is costly and aggravating for drivers, and it can also be dangerous.

The 2018 OIG report found that a 15-minute increase in the total time a truck spent at a facility increased the average expected crash rate by 6.2% — an additional 6,509 crashes for the year studied.

Delays at the loading dock can disrupt drivers’ sleeping schedules, which lead to fatigue on the road. In other cases, a driver may push harder and drive more aggressively to make up for lost time spent waiting at a facility.

For Eme, detention is just one more part of the job out of his control.

“Every day, there is a possibility for unpredictability,” he said.