Dear LAist: Why Is Traffic Lighter On Friday Mornings?

Fridays hold a special place in the hearts of commuting Americans. We're looking forward to the weekend, planning our evenings secure in the knowledge that we don't have to be presentable in any way come morning, and just generally feeling ourselves as we head in to the last day of work for the week.

For all those reasons, the commute might feel a little...lighter. Shorter. Less intense than, say, on a Tuesday. Which might be why one of our readers, Tarin Almstedt, wrote in to ask why traffic is lighter on Fridays than on other days.

"I commute into Los Angeles 26 miles one way, literally a marathon daily," Tarin wrote. "Why is traffic lighter Friday mornings than other mornings?

To answer Tarin's question, we first examined whether the assumption in the question was correct. Is traffic, in fact, lighter on Fridays than on other mornings? Or are we all just so deep in our Lizzo-inspired playlists that we don't even notice the time flying by?

The answer is pretty straightforward. After crunching the numbers, Michael Comeaux, a representative from CalTrans, replied in the affirmative.

"Delays on Friday AM are much less than all other weekdays," he told us in an email.

Okay, so that's that. But what are the specifics? And why is this happening?

According to the data Comeaux sent us, using the week of May 5 as an example, vehicles traveling on freeways throughout Los Angeles County between 6:00 a.m. and 10:00 a.m. -- the official L.A. morning rush hour -- were delayed a total of 52,073 hours. That compares to a total delay of 58,352 hours on Monday, 68,565 on Tuesday, 74,821 on Wednesday and 63,735 on Thursday of that week.

Additionally, tracking the total number of miles traveled by cars in L.A. County during the same hours and the same week, CalTrans found that fewer total miles were driven by all cars on the road on Friday morning than on other mornings - in other words, traffic was lighter.

This finding was corroborated by Gabriel Kahn, the publisher and editor of Crosstown, a data-driven effort based out of the USC Annenberg School for Journalism that's looking for new ways to understand L.A. He told us that the average speed on the 10 Freeway going from downtown to Santa Monica between the hours of 7 a.m. and 9 a.m. was 45.16 miles per hour Mondays through Thursdays, and 46.92 on Fridays (Kahn's team measured these numbers between February and June, 2018).

During the same time of morning, traffic headed north on the 5 Freeway into DTLA averaged 37.6 mph Monday through Thursday, and rose to an average of 43.7 mph on Fridays.

While we can never be 100% certain why traffic on Friday mornings offers this welcome (albeit slight) respite, Comeaux has some theories.

"Many people take Fridays off, or work a modified work schedule on Fridays," he says. "More people work early on Friday to ensure they do not have to work late, hence morning traffic is more evenly distributed."

Whatever the reason, we invite you to lean in to the now-confirmed fact of lighter Friday morning traffic, and enjoy yet another occasion to celebrate the day.

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