Blowing Through the Traffic Model on I-94

In class we discussed about how adding a superhighway would actually bring the whole society down in terms of increased delay. Last week I was driving on I-94 and took the expressway to get home in no time at all. While I was zipping by on the express, literally two lanes over in the non-express part of I-94, drivers were stuck in traffic for miles on end. We assumed in the traffic model that people would take the roads with less delay, and eventually when enough drivers fill up all the pathways, all delays would be equal and thus be in an equilibrium.

But does it really work like that? I feel like that model is only valid when the driver knows ahead of time all the delays each path would result in. I-94 is three to four lanes wide, and most drivers assume that there wouldn't be any traffic because there is so much roadway, so they never bother to take the expressway. So unless the individual knew way ahead of time that traffic would occur on I-94, they would never take the expressway, leaving the expressway constantly unclogged because people cannot make decisions fast enough for an equilibrium to take place.

I feel like this also could be said of a drivers decision to choose which lane to be in. You know how no matter what lane you choose, it seems like the people in the lanes on either side of you are moving, and you're in the only lane at a dead stop? Then everyone in your lane wants to switch lanes, and eventually your lane is moving and the other lanes are all stopped. But then, just as before, everyone wants to cut back into your lane... making traffic stop again. This stop and go traffic sucks but i dont think that most people realize that they're probably better off just staying in their original lane.

I know that the times you've taken it, you've been better off in the express lane, but I think I'm more at a 60% success rate with the express lane. All's going well most of the time...until the one person in the express lane decides to go 40 mph when the speed limit's at 55 and everyone ends up trailing him/her while the people in the regular lanes maintain a 60-70 mph speed.

So, I think the overall delay in the express vs. nonexpress lanes are due to luck (as well as the lack of information you mentioned, similar to the lemons example in class with seller knowing more than buyers) with who happens to be in the express lane at the moment you enter. You can't predict how often a slow driver will be there, but some people would definitely try their luck at weaving in and out of traffic to get ahead over taking the express lane.

The problem could easily be fixed with a high minimum speed limit being posted for the express lane only so that faster drives can go in those lanes and make the other lanes safer. Plus, everyone would be happier. Although, if people know they would never get stuck behind a slow driver in the express lane, I'm sure it would be more popular and I-94 drivers would take it more often and it would reach equilibrium as we discussed in class.

Is there a potential downside for taking the expressway? Assuming the majority of people in the non-express part of I-94 were not exiting in that block of local roads and they figured it would be no different from the express part, they should choose randomly and statistically even out into a relatively even split. Given this, maybe the non-express part was primarily made up of drivers who could not use the express part and were backed up due to local traffic. Even if the people who were not getting off there split evenly between the two sides, the people getting off there might have slowed it down so it seemed like more people take that option and made it even worse.