Just where is the busiest freeway in North America?

While the United States may have the largest road network in the world, the title of the busiest freeway on the continent belongs to their neighbors up north in Canada with its Ontario Highway 401.

Known as King’s Highway 401, the freeway also goes by its official name of the Macdonald–Cartier Freeway. A 400-Series Highway in the Canadian province of Ontario, the 401 stretches from Windsor to the Quebec border. The segment of Highway 401 passing through Toronto is not only the busiest highway in North America but also one of the widest and busiest in the world.

So, what makes this freeway so busy? According to a report from the Federal Highway Administration, the annual average daily traffic (AADT) count between Weston Road and Highway 400 in Toronto was estimated at 431,900. On some days, the number exceeds 500,000 vehicles.

Those stats make the 401 the the busiest roadway in North America, surpassing those in the U.S., including the Santa Monica Freeway in Los Angeles, Interstate 10 (I-10) in Houston, and I-75 in Atlanta.

Have you driven on Ontario Highway 401? What was your experience like? Be sure to let us know in the comments below.

Image: Danielle Scott, PLTam

  1. Be careful when you say “much bigger cities”…..you might be misleading.
    The GTA alone is FIVE TIMES the size of NYC. Not to mention, if you’re traveling through NYC, you’re going from nowhere to nowhere. If you’re traveling through Toronto, you could be just crossing town…..or on a 300-500 mile trip across a province that’s 8 times the size of New York State!

  2. Did you mean to say “OUR” government?
    401 less busy in London? Duh.

  3. Except that the 401 doesn’t touch the vast majority of the province of Ontario. The stretch it does borders 4 states along Lakes Ontario and Erie.

  4. Population yes, but geographical area?

  5. I just moved (and drove) from Albuquerque to Montreal for college, and I can honestly say the worst traffic I’ve ever seen, including Bangkok and LA, was the 401 in Toronto. I almost had a heart attack and saw TWO pileups caused by people passing on the right and swerving back into the fast lane.

  6. It’s horrible. I hate crossing Toronto because you never know what you’re going to get.

  7. The 401 is an amazing highway. I have been all over the world but I’ve never seen a highway approaching the both size and volume of the 401. I’ve been on the I-10 in Houston and it is the widest at some points for short distances – but Toronto’s 12-18 lane collector/express system stretches for over 30 miles and it’s being extended to 50 miles. Furthermore the volume is double the I-10 in Houston – which means it’s crawling for a good chunk of the day. Furthermore, it is the world’s busiest truck route due to the close proximity to the US border and our integrated auto manufacturing system between Michigan and Ontario. Finally, it’s a shortcut for Americans between Chicago/Detroit and Buffalo/Boston. It’s Toronto’s circulation system, usually on the verge of a heart attack due to clotting.

  8. Outside of the GTA, the traffic pretty routinely zips along at 130 – 140 kmph. Even in snowy conditions, expect a lot of people to be pushing 110. Except when there’s an accident and it backs up instantly for huge distances because of the volume.

    And yeah .. around Toronto, it’s busy pretty much all the time except for rush hour, when it’s insanely slow. LA thinks they have bad traffic, but Toronto has it worse. Fortunately, most of the T.O. drivers are pretty good at cooperating with each other to get everyone where they’re going. Not all of them .. but compared to everywhere else I’ve driven, it’s like collaborate driving Nirvana, so long as you enjoy 15 kmph.

  9. Actually, a freeway where Kingston road is would kick ass!

  10. Also, someone should run the Allen down to the Gardiner and tell the richie Cedarvale people to SHUT UP already.

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