Travel Hacking SFO… the Daily Commute Edition

a bus parked outside of a building

If you read this blog and follow others in the Boarding Area, you’ve probably invested hundreds of hours optimizing your experience in the air.  But, have you done the same with your daily commute at a lower altitude?  Now that Citi Thankyou Premier has taken the lead to include gas in its “travel” bonus category, it’s time for someone in this hobby to write about America’s favorite mode of travel: cars.

A year ago, Terence wrote about travel hacking SFO: by creatively utilizing the connectedness before and after security check points at Domestic Terminal 3 and International Terminal G, he skips wait lines like a pro.  The concept is endlessly fascinating, and an infrequent traveler like me could hardly grasp how one goes about figuring it out.  The flights that I take are few and far between, and the one time I remembered to look up his method after booking my trip, I wasn’t even flying out of either terminal.

Well, I do one thing with SFO more frequently than Terence: looking at it.  My condo faces its main runways and I can see the planes from the living room without putting on my glasses.  Whenever I make a junk food run to my neighborhood McDonald’s, I technically drive by the airport.  As such, I consider myself more familiar with the roads leading in and out of SFO, than the majority of the people who actually use it.

Now, ladies and gentlemen, I present to you the other actuary’s travel hacking tip: bypassing 101 traffic by leveraging the airport.

101 is a key artery in the Bay Area’s freeway system.  Like the Belt Way around DC and the LIE in Queens, this road can get congested to a halt several times a day.  When that happens, my tip will help you go around that traffic for the entire length of San Bruno, a two-mile stretch.  Sure, it won’t be performing miracles for those of you en route from San Francisco to San Jose.  But, for those living a quarter mile at a time, this difference can be night and day.  As for me personally, the majority of the gas that I burn fuels the daily trips from my Millbrae home to pick up kids at their South San Francisco day care.  The amount of 101 traffic I can bypass with this hack is a considerable portion of my entire trip.



Let’s start with the southbound.  During the evening rush hour, cars tend to pile up in this direction.  The key to this hack is the freeway exit right after the 380 junction, at the south end of South San Francisco.

These signs point to many destinations, none of which is particularly inviting for the average commuter.

And that’s the beauty of it.  Go ahead and take the exit, and you’ll find yourself on a very long “ramp” with three lanes that run parallel to 101.  Let’s call it the SFO access road.  Multiple merges in and out connect this SFO access road to the various exits that the signs promised, and eventually it will lead to the airport… oh wait, just kidding!  I’m supposed to go home and feed the kids!  Thank goodness there’s a ramp that connects you back to 101.


Ta-da!  Now I have just pretended wanting to visit SFO, only to change my mind last minute and continue driving on 101.  See the map below.  The two paths are both 1.5 miles.  In light traffic conditions, the SFO access road will take slightly longer due to its lower posted speed limit (40 MPH).  During rush hour, however, it likely still has a nice flow while the same can’t be said about 101.  Time and over again, I had watched hundreds of cars stuck in <20 MPH jams while my kids in the back seats cruised by at 60.  That’s a solid 3-minute saving right there!




The title of this post comes in when you take the tip one step further and actually head into SFO, make a loop, and head back out to the freeway.  You know, what you do when picking up an out-of-towner, only to realize that the flight had been delayed.  In theory, you have four options: (1) domestic departure, (2) domestic arrival, (3) international departure, and (4) international arrival.  A trip around the international terminals is half as long as a trip around the domestic terminals, so that’s what we should do.  My default is to use the international departure, although the arrival level may work just as well.  When I make a quick visit and then look for the exit toward 101 south again, the ramp places me another half mile down the freeway.

Not everyone expects this view this on their way home from work.


As the Google Maps comparison indicates, we are now making a serious detour.  Relative to the “basic” version, we’d be driving an extra 1.5 miles to skip traffic for 0.5 miles.  Is it worth it?  Well, let’s do the math:

  • 2 miles on the freeway, in heavy traffic at 30 MPH – 4 minutes
  • 2 miles on the freeway, in congested traffic at 15 MPH – 8 minutes
  • 3 miles detour through SFO, at 40 MPH for 2.5 miles (access road and ramps) and 20 MPH for 0.5 miles – 5.25 minutes

As you can see, it doesn’t make sense to go through the terminals under normal circumstances, but when the congestion gets dire it can be a time saver.

In reality, traffic flow on 101 sometimes gets worse than 15 MPH, while at the same time you can get away with driving much faster into and out of the airport (just not through the terminals… we don’t want to run over any frequent flyer friends).  When the conditions are right, you can easily save 5 to 10 minutes by doing this.



The SFO exit on the other side of 101, surprisingly, requires you to enter the airport.  As such, you have to commit to a detour when using this travel hack.  The advantage is that ramps leading in and out of the airport are more straightforward, so your detour is about 0.7 mile (as compared to one mile on the southbound direction).  Also, you get to avoid an additional half mile of 101 in this direction.  When the traffic gets hectic on the main road, you bet I’d be bypassing it 2.5 miles at a time while saying hi to my favorite airport.




Let’s face it:  driving by the terminals when nobody in your car has a boarding pass can be awkward.  Is there a way around it?

Turns out it’s possible to enter the airport and head right back out, without actually reaching any of the terminals: follow signs for domestic arrival, head toward the hourly parking garage, then make a u-turn right before the garage:

That barely visible sign is the key.  No part of this commute hacking involves using the hourly parking garage.

When executing this right, you can shorten the detour by 0.2 miles!  But I hesitate to advise this route because:

  • You need to merge in and out of domestic terminal traffic, which can be unpredictable and troublesome
  • If you are heading north, the amount of lane changes after the u-turn can be hazardous
  • A stop sign is involved…



Before everyone ditches the comfortable freeway and takes a joy ride through the airport, let’s just be clear that this travel hack (aside from the basic southbound version) is useful only when traffic on 101 gets seriously bad.  Rush hour, major event, and accident can all be good triggers, but I would not expect to need it on every trip.  Check your smart phone to see how bad the traffic is, or simply eyeball the density of cars ahead of you.  When it’s becoming a bumper-to-bumper situation, or if cars are braking to under 40 MPH, you might want to consider this detour.  I like to hedge my bets by driving on the right lane when approaching the airport exits in either direction.  This way, if I have a last-minute realization of the traffic condition, I can make a split-second decision on which path to take.


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