Today in "what the heck just happened?" we have a stream of empty, slow-moving dump trucks blaring their horns along the Gardiner Expressway for a solid hour.

Truck drivers caused a traffic jam on the Gardiner this morning in a protest against commercial insurance rates - 📹 AreaCode416ix https://t.co/MrjvsKqsae pic.twitter.com/dbx62Z948n

— blogTO (@blogTO) May 1, 2019

If you didn't hear the commotion, count yourself lucky. It was loud, annoying and it slowed down traffic quite a bit during rush hour on Wednesday morning  — but it wasn't just for kicks.

The truckers were protesting rising commercial insurance rates, according to witnesses and those involved in the demonstration. 

Rules for a truck protest: always be beepin 🚚🚚🚚#Toronto pic.twitter.com/1EbZUgsEjm

— CatSharky 🐱🦈 (@Cat_Sharky) May 1, 2019

"Insurance kills truckers: reason for this crazy protest on the Toronto highways," wrote a Redditor who shared video footage from the middle of the protest around 9 a.m.

"That's what the I believe two cars leading the convoy at the front had written on them."

Commercial INSURANCE RATES MUST GO DOWN ❌❌❌❌🙏🏽Shoutout to the truckers out here today.
.#insurance #commercial #trucking #hwy401 #401 #brampton #sarpanch #toronto #mississauga pic.twitter.com/1LnzgvXpay

— 401_da_sarpanch (@401_da) May 1, 2019

A Twitter account that bills itself as the "official Highway 401 Trucker Page" live-tweeted the event, writing such things as "Commercial insurance rates better act right soon" and "PROTEST WON'T STOP."

A photo shared by that account just before 7 a.m. on Wednesday showed about half-a-dozen truck drivers holding signs with messages like "Honk if you hate your truck insurance" and "commercial insurance kills."

High Insurance Rates Stop Now 🛑❌ high Commercial insurance rates is affecting thousands and the entire industry.
.#hwy401 #401 #sarpanch #toronto #brampton #mississauga pic.twitter.com/ZOuldDjWsl

— 401_da_sarpanch (@401_da) May 1, 2019

Drivers and people who live near the Gardiner may have been sympathetic to the cause, had they known what was going on, but most of them didn't.

Symphony of Trucks this am in #toronto pic.twitter.com/DO6mrmJY1y

— Andrea Crisp (@misscrispy) May 1, 2019

It was for this reason that Twitter exploded in anger over all the trucks blocking off traffic with their horns honking and lights flashing along a very busy downtown freeway.

What shenanigans are this on the Gardiner, with this convoy of truckers honking non-stop and slowing the middle lane of traffic to a near stop? #toronto @CP24 @NEWSTALK1010 pic.twitter.com/sRYYtZAtT2

— Elle (@gleefulreader) May 1, 2019

"I live next to the Gardiner and their honking is irritating as fuck right now," commented one downtown resident on Reddit. "They're blocking 3 lanes right now."

"I wish groups would stop protesting on the 401," wrote someone else. "It's already a nightmare to drive, and you're inconveniencing thousands of not just commuters, but families and tourists who are just trying to use the only E-W artery to get across the GTA."

Truck convoy going through Toronto right now! pic.twitter.com/ccEYi4TGtQ

— Laura Selman (@laura_selman) May 1, 2019

After slowly moving down the Gardiner, the convoy is said to have went north up the Don Valley Parkway and then onto the 401.

Whether or not their protest will actually impact commercial insurance rates remains to be seen, but the truckers certainly got plenty of attention from the people of Toronto.