The Diagonal Cross

Today is a post about biking the streets out here. I wanted to introduce you to an advanced technique which I had seen done before but had not yet thought through. So, I spent some time thinking about how this would work and then began to test out my technique. So far, I'm still alive.

This advanced technique is what I call the diagonal cross. That's right... crossing the street diagonally

The typical intersection light timing cycle works like this:
1. 40 seconds for straight traffic (say, north-south).
2. 10 seconds for left-turn traffic (northwest and southeast).
3. Then, 40 seconds for cross straight traffic (east-west).
4. 10 seconds for left-turn traffic (northeast and soutwest).

Simple enough. Consistent. And every stoplight has a timer that lets you know how many seconds remaining in that phase of the cycle. So, no sudden yellows and strandedness.

So, imagine I am on the southeast corner of an intersection, and I want to cross diagonally to the northwest corner. Here I am, waiting through the 40-second north-south straight traffic phase.




Here is how the diagonal cross works. As long as you're ready, you use the 10 second left-turn phase that follows:



... and you bike between the arrows. Sure you're trusting that the cars coming from your left will really turn left and not run you over. And sure, you're trusting that the cars coming towards you from your right really will turn left and avoid you. But, 10 seconds is a lot of time to make it across diagonally on a bike.

I think the key to this advanced trick is to know when the diagonal cross is available to you. If you have to stop and think to yourself, "Wait, could I have just crossed that way... right through the diagonal?" and you're examining the lights and the cars... then you've probably lost 5 seconds in your window, and now you'll never make it.

I will have to practice this one this week.