As an adult on the west coast of the US, I've been driving for many years. On the freeway, in the suburbs, in the city. While I'm lucky to live in a relatively low traffic major city, I've felt the experience of traffic frustration many times over. For the last couple of years though, I've been living in the heart of the city, and walking as my primary form of transportation.

I still own a car, but it sits in the garage nearly all of the time, with use about once per week. So, now I see the world a little differently. With my point of view as a pedestrian and my many years behind the wheel, I have led to a theory of what causes much (most?) of the traffic jams major cities experience.

Pedestrians. Pedestrians like me are why city streets experience traffic problems.

I can't tell you how many times I've sat in traffic where it took two, three, four, even five cycles of a traffic light before I got through an intersection. Only to be stuck at the next one. How many times have you turned a corner, often onto a major street, only to see a line of cars in front of you, barely moving?

Blame pedestrians.

See, nearly every traffic signal includes signals for pedestrians. They tend to indicate: walk, a warning not to walk, and then don't walk. Walk means go ahead and step off the curb and start crossing the street. Its often a green hand, green/white icon of a person, or event he word "walk." The next symbol is a countdown to the changing of the traffic flow. It is often indicated by a flashing red hand, or flashing red icon of a person. It means do not step off the curb, do not enter the intersection. If you are already crossing, you have a limited amount of time to get to the other side of the street. And of course, there is the 'don't walk at all' sign, indicating that you shouldn't be in the intersection at all, typically because of the oncoming traffic.

Unfortunately, pedestrians don't interpret the signs as I've described above, with three stages. My observations show that pedestrians look at those signs in a very binary way. Two stages. Cross, don't cross. The subtle difference between what is intended and how its interpreting is that much of the time, the signal is indicating not to step off the curb, but continue crossing if you already have. Yet, many pedestrians will continue to step off the curb as long as they think they can cross before the countdown is down, or in some cases they'll step off the curb as long as the countdown is still going, even if its down to 1 second before the signal changes.

I'm not trying to be a stick in the mud, or a grumpy old man, but there is a practical implication here. Those signs are set as such in order to allow cars, trucks, buses, and bikes to have an opportunity to turn right or left. As long as pedestrians are in the intersection or stepping off the curb, traffic cannot turn. When they can't turn, they do not move. When they don't move, traffic backs up. On and on and on it goes.

So, to ease traffic we need to clear the way for traffic to turn. To do that, we need pedestrians to follow the signs, and thus following the law. Easy, right?

Nearly impossible.

I think about this problem nearly every day that I walk to and from work, and I haven't landed on a reasonable solution. Hand out traffic tickets to pedestrians? Install physical barriers at crosswalks? Shame pedestrians for stepping off the curb when they shouldn't? Change the symbols on the signals? None of these options seem to have both the intended result while also being practical/realistic.

It appears that the solution employed by some cities, at select major intersections, is to place a traffic officer in the middle of the intersection with white gloves and a whistle. I always thought that they were there to direct vehicle traffic. Now I realize that they are there to direct pedestrian traffic. Stopping them from entering the intersection so that vehicles can make their turns, reducing traffic down behind them. It seems to work, but its not practical at the large scale. Traffic on the streets of downtown Portland is terrible during rush hour. The city would have to deploy dozens of officers, give days a week, to manage these intersections. Not a good use of police officer time, if you ask me.

So, do you agree? Are pedestrians a significant reason city streets experience traffic? Are there ways to solve this problem, which are both effective and practical? Let me know over on Facebook or Twitter, using the links below!

I wonder how a firm like IDEO would approach the solution?