Q: “Two quasi-experiments”?  To start, can you explain what this means?

Firstly, it’s two experiments because there were two phenomena of interest.  First, drivers quitting, and second, tight markets.   We wondered, what’s different in the ELD data between a driver about to quit and one who isn’t; and secondly, what’s different in the ELD data when we compare a soft and tight market?  It’s called ‘quasi’ experiment because we didn’t design a dedicated experiment. We’re being opportunistic, using both drivers quitting and market cycles as natural experiments.

Q2:  Driver turnover is on everyone’s mind.  What do you find?  What’s different in the ELDS of drivers about to quit?

We compared weeks that preceded a driver quitting to weeks that didn’t.  What’s different?  Drivers drive less if they are going to quit next week – especially on weekends and especially on weekends in tight markets.  To me, this – and some other results – indicate that profit maximizing drivers seize profit opportunities by driving more on weekends.  Also, in the weeks that preceded drivers quitting, we observed that they were sent to comparatively freight sparse locations.

Q3:  What about soft and tight markets?  What’s the difference in the ELDs?

The first thing is that drivers drive more in tight markets.  When you measure freight transportation capacity by hours driven, these results show that it expands in the tight market.  But, the analysis shows that while drivers are de jure capped at 11 hours driving/day by the FMCSA, they are de facto capped at ~7.  This is especially true on Tuesdays, Wednesdays and Thursdays. In tight markets, drivers seize the profit opportunities on Saturdays and Sundays.

Q4:  What does this mean for shippers struggling to find capacity in tight markets?

Two things. First, if you want extra TL capacity in tight markets, it’s there – but it’s there on Saturdays and Sundays. So schedule and staff your DCs in order to avail yourself of that opportunity. It’s hidden in plain sight.  Second, in tight markets, I observe that dispatchers send their drivers to comparatively lower average dwell time facilities.  So tight markets should be a reminder to every shipper and receiver that your reputation for dwell precedes you – especially in tight markets. 

Q5:  What’s next in this research?

I mentioned that drivers are de jure capped at 11 driving hours per day by the FMCSA, but seem to be de facto capped at 7 hours per day by something else.  Well, what’s that something else?  We’re going to keep digging until we find out.   I’ve got some brilliant students and highly motivated research partners cracking on exactly that right now.

You can read the full working paper, “Two Quasi Experiments Concerning Working Conditions of American Truck Drivers” at this link.