People spend a lot of time solving the traffic problem, but I always figured they were further than they really are...
People that enjoy math tend to appreciate complex problems, especially problems that have more than one solution, and possibly more than one optimal solution. That makes traffic congestion an ideal problem for people to try and solve. Using Seattle and LA as examples, I think the constituents of these two great cities would both agree our air is cleaner in Seattle and that traffic sucks. You really can't appreciate traffic until you've lived in it for a while, growing up in Washington DC, we had one of the worst kinds of traffic, grid-lock. Also known as stop-and-go traffic (I prefer to call it stop and nap traffic), the type of impact such a blockage has on a system is profound, since it maximizes density and prevents any form of parallel or dynamic movement of all elements that make up the blockage.
I am going to be using the following article from LANL to help me out here http://xxx.lanl.gov/PS_cache/nlin/pdf/0404/0404018.pdf, with the recommendation that reading said article will probably put you to sleep and at the same time piss you off that so much money is being spent on traffic congestion and the state of the art happens to be heuristic diagrams telling us that under certain conditions a traffic jam can occur. I think we already knew that, in fact if they had just polled thousands of real people they would have quickly realized we already came up with their pretty equations in the 6 years of our life we lost in traffic.
Anwyay, let's start down in LA. They've recently been using a vector space computer in order to solve a bunch of their traffic problems. Concentrating on two primary areas. The first is a kind of goliath AI system that tries to predict character behavior of drivers. This has been done before with the most notable occurence of recent times being the system used to create the fields of Orcs in LotR. In the traffic system they try to predict in traffic based on someone's average day (driving to and from work), and then spice it up with special events (heading back into the city for ice cream). The system works out pretty well, and the more time they spend on the AI, the more it will mimic natural human behavior on the statistical scale. That seems like good use of tax payer dollars right?
They've gone an additional step and tried to actually use the system to make some changes. The concepts of a priority bus line are in play right now, and by adding a bus only lane of traffic they've found they can cut down on the amount of foot and car traffic throughout certain portions of the city and nearly double the number of times for pick-up and drop off at various bus stops. Would you ride the bus more if the schedules were more granular and the bus got you there on time? I know a lot of people that have started taking the bus because it is a period of their day where they don't lose time. You can read on the bus, write your presentations, now if they only offered Wi-Fi ;-)
Looking at the traffic situations of some of the major cities I think Seattle generally overpromotes their traffic issues. If you read the article above, we are lucky enough to fall into a specific category in the diagram known as Category III traffic or densely congested traffic. In this model, there is the ability for traffic to move as a single beast, albeit a slow beast, cars are able to rapidly accelerate off the front of this jam when space is available (generally after highway merge zones), cars in the jam can maintain some consistent speed (generally between 25-45 mph), and cars that are approaching the jam don't incur the sudden-stop penalty. It is much harder to get your car moving than to keep it moving at a slow rate.
Now, you'll say, you've been in some stop-and-go situations, but I'd argue not really. Generally stop-and-go situations in Seattle arise when you are on a ramp or merger. This isn't necessarily traffic, as much as a necessary choke-point. After all, you are upsetting the equilibrium of the system by trying to increase the density of the traffic that is already moving at a good clip. Good road-way design (at higher costs) can get around much of these problems. I'm sure everyone has wondered why they have areas with a lane that exists as a merge-on and merge-off zone with cars adhering to the zipper effect, with a single moron able to ruin the entire process (ever had one lock in a zipper fail, ick). Well, those zones are much cheaper to produce, require less land, and work optimally in low density situations, but tend to fail during higher density situations since you are effectively doubling the maximum effective density of the lane.
To end, I'm always curious what Washington state is doing when it comes to traffic. We supposedly have one of the most unique and volatile traffic situations in the entire country, yet all of the good literature is coming out of other major cities. I believe that we are actually in the infancy of possible traffic problems and that we are actually solving the same issues large cities solved nearly 30 years ago. Look at our current solutions, and you'll see techniques from the past. The creation of a light rail is certainly nothing new, improved car-pooling initiatives (don't even get me started on the moronic layout of HOV lanes compared to the highly optimized layout of HOV channels used in other cities) have been done while we follow suit, and I still think a lot of seattle'ites are pissed that we really aren't doing much to improve the bus system (clearly one of the most effective solutions based on the numbers coming out of LA's department of transportation). At the end of the day, our traffic isn't that bad, but we are getting charged a lot to fix it. I'm not sure I'm too happy with that.