Wednesday, April 04, 2012

A guide to flow tricks for the 101 freeway in the silicon valley

In driving on the mean streets of the silicon valley I am sure you will notice there are weird instances where traffic makes no fucking logic.  I can remember the first instance I noticed of this was when I would drive to my job in Los Gatos from my parents house in evergreen.  This was before 85 was completed so I took 101 to 280/680 and then 17.  After you get past downtown there is a gyre of traffic badness that often requires three lane switches in just a few miles for optimum flow.

Driving home from my current place of employ I usually take 101 the whole way.  This takes me from Ellis out to Coyote Valley.  Driving this I have watched and watched how the slow lane often becomes the fast lane and then turns into a traffic jam later on.  At first I could just not wrap my head around this.  At first you want to blame your fellow drivers and driving through Evergreen you are going to be right.  Sorry Evergreeners I understand they overdeveloped your area with regard to the freeway connections but you also drive like fucking pricks.

What I began to see was a pattern of traffic as a stream with hidden obstructions underwater that were driving traffic.  This was closer to the truth but certainly a flawed view of things.  There is nothing under the road that effects us barring some small driving changes based on road quality.  What I have come to see traffic flow as being like is the vascular system.  With off and on ramps representing the smaller connecting capillaries.

So in looking at our freeway system you will notice the larger connections to a given freeway act as a place of vascular resistance.  There are exceptions here due to the drivers free will but generally any major connection is going to be a location many drivers will want to drive to.  When driving you are going to want to opt for a more traditional fast lane placement as the exiting lanes are unable to handle the flow they are being given and back up.

For non prominent exits these take pressure more naturally and therefore the slow lane now speeds up having just lost traffic density.  You are going to want to take advantage of this relationship.

That is basically it in theory, more generally it could be said traffic is caused by civil engineering fuck up that constantly fail to account for the number of cars on the road.

I wasn't going to detail my route in case no one realized I didn't understand what I was talking about and started using this but what the hell.  So for me I get as far to the left on Bayshore as possible when leaving Ellis as the connection too 237 backs up traffic horribly.  From here I see how fast traffic is going, If max flow has not been reached I play it by ear.  When traffic flow tips into a jam I move over to the slow lanes.  I will do this starting around Fair Oaks.  I will continue until in the slow lane until sometime before Lafayette street; where you see Airsoft Extreme.  I am going to stick to the left until just before the cut over to 87/Guadalupe.  I don't want to turn so I am getting over just as soon as the lane clears up so i can go fast.  I am actually going to get into the new left lane that is created when the first street people merge onto 101.  That is going to give you a quarter mile of fast then i hop into the two lane just after The Nimitz (880). 

Starting here i work over back to the fast lane.  I am not sure why but the slow lane really is the slow lane anytime you have a long stretch between exits.  I usually start working toward the slow lane between McKee and 280/680. The Sinclair freeway connection is one of the arterial connections where traffic naturally slows so you do not want to be in the slow lane. BUT! Immediately after the road speeds up after the story exit.  This is one of the best tricks on 101 but you have to be careful.  A stray slow driver will kill this and you have to merge over by the 680 merges onto 101.

Ah now you are in Evergreen and sort of screwed.  Tully takes some traffic but the road work going on is a killer. My best advice is try for the number two lane and ride it half way to Capital expressway. Here work your way to the fast lane.  One you get past the bottleneck you are home free.  Hellyer and Blossom Hill are really nothing and traffic should be nearing max flow at this point.

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