WTH Are You Doing?!

I'm currently on a Spring co-op cycle, and during the summer months, I commute from my home in New Hampshire into Boston. Ideally, this trip takes between 40-50 minutes, but with rush hour traffic  (which is what I was driving in) that time quickly rises to nearly 2hrs. At some points along the route, cars would come to a crawl of around 5mph for a couple miles, yet people still tried to weave in and out of lanes to try to get ahead.

It drove me insane...

For the first couple of weeks, I'd be frazzled and stressed by the time I made it to work. Constantly having to watch out for drivers cutting me off, tired/distracted people not paying attention and rear ending me, or crazy drivers narrowly avoiding smashing into other cars around me was exhausting and extremely aggravating. Eventually, I started to know when I was coming up on a spot on my commute that regularly had bad traffic and could start mentally preparing myself. I'd usually do that by trying to think of a problem or idea that would keep me pondering and distracted until traffic cleared.

One day, the thought that popped into my head was "why is there traffic?". That question became my go to for the remaining few months that I had to drive into work.

I began to keep track of when there was and wasn't traffic, and the different factors and driving conditions of those areas. Some places that have the worst stretches of bumper to bumper cars made sense. Poorly designed merges that caused people to have to stop or hit their brakes, construction, signs warning about construction (even if there wasn't actually construction), weather, accidents and/or popular exits were the usual culprits. But there remained one or two spots on my commute that had no obvious cause. I was stumped. I couldn't come up with a reasonable explanation which was frustrating, but I preferred thinking about that over yelling at the crazy drivers around me.

Some days I got lucky and got to take my Dad's car to work. He has a newer Volvo that comes equipped with adaptive cruise control. You choose the speed that you want to be your maximum, how far you want to stay from the car in front of you, and then the car does the rest itself. It will speed up, slow down and even come to a complete stop. It was great in stop and go traffic because I could set it and relax letting the car do most of the work for me. Once I'd experimented enough to trust it, I began to use it for the entire commute.

On a particularly lousy Monday, I had the speed set to 75mph and was cruising along while humming to whatever song was on the radio. Suddenly, the brake lights of the car in front of me light up, and the car starts to slowdown. I hesitate waiting for the cruise control to adjust my speed, but it doesn't do anything. I quickly hit my brakes and drop my speed down to 65mph. By the time that I had slowed down, the car that had caused me to brake had already accelerated and sped off. I realized that the driver of the car ahead of me hadn't been paying attention and was startled by how close they had gotten to the car in front of them which caused them to tap their brakes. The Volvo, which uses radar to detect speed changes, knew that yes, the car in front of me was braking but not hard enough for me to have to slowdown. Me being a human, I saw the red brake lights and momentarily panicked which probably caused the person behind me to do the same thing. I dropped to about 6/7 of my current speed. If the person behind me did the same, it wouldn't be long before a chain reaction of light brake taps brought a car to a stop. I might have just created a traffic jam.

After having that realization, I noticed how often cars around me braked without having to. Over reactions combined with people who actually have to brake to avoid colliding with some dingus that cut them off would explain the traffic that I previously couldn't explain. And come to find out, using the power of data and math that is indeed Why Traffic Happens.