When freeway is shut down, where did the cars go?

It's common for armchair transportation experts to write letters to the editor pointing out the "gridlock" at this or that section of freeway as a reason we need to constantly add more asphalt - - adding to an infrastructure that the states cannot afford to maintain as it is. This is the "when you're gaining weight, buy bigger pants" solution America has long embraced.

But, as we've seen here in Milwaukee during the Marquette Interchange shutdown, traffic miraculously finds a way to compensate when well-used routes are impassible over a predictable period of time (as opposed to surprise shutdowns).

From The Seattle Times, via The Political Environment:

We just discovered I-5 solution

By Danny Westneat
Seattle Times staff columnist

In the case of the vanishing cars, the plot thickens.

The state has reopened our busiest freeway, Interstate 5, after a two-week partial shutdown. The dawn-to-dusk traffic apocalypse never arrived. But what we still don't really know is: Why? How? Where in the world did all the cars go?

The theories are as plentiful as empty seats will be this week on the Sounder trains. It's been said that people left on vacation. Or telecommuted. Or took mass transit in droves.

It turns out none of these is true. At least not in big enough numbers to explain the smooth driving these past two weeks.

Take the transit myth. If you add all the trains, buses, van pools and water taxis, about 2,500 people per day hopped a ride who don't usually.

That's fine, but I-5 carries 130,000 cars per day just in the northbound lanes. Yet traffic was down there as much as 50,000 cars a day. Transit can account for maybe 5 percent of these missing cars.

So I asked two smart traffic people: Where did the cars go?

Their answers suggest a way to solve our traffic mess. Without spending much money. And without building new freeways.

I asked that Redmond math whiz, Oliver Downs, the guy who predicted there'd be no gridlock. His firm, Inrix, gets official traffic counts as well as instant data from thousands of cars out driving local roads.

He compared traffic the week before I-5 was shut down with the project's first week. He found that, across all highways in and around Seattle, traffic dropped only 4 percent.

"It's fascinating," he says. "The cars didn't vanish at all. They diffused."

What does this mean? Dave McCormick, of the state Department of Transportation, says people drove differently.

"The traffic mostly shifted and spread," he says — shifted slightly to other routes, and spread substantially to other times of day.

So it wasn't that folks left town or flocked to transit or stopped running errands. They changed how and when they drove, but they kept on driving.

So here's my idea: Let's replicate what just happened. We already restrict cars from using Third Avenue downtown at rush hours. Now let's do that on the major freeways.

We could set up a license-plate cordon around downtown Seattle. Drivers with, say, even plate numbers could drive in at rush hour some days, while those with odd numbers get the privilege the other days.

It could be enforced with license-plate cameras and a small fine. If it's not your day, you'd have to take transit, car-pool with someone who has privileges that day or, as in these past two weeks, alter your route or shift to a non-rush-hour time. Commercial plates could be exempt.

There's no toll, so it's equitable. It's practically cost-free. It would instantly ease congestion without new freeways. It would likely allow us to tear down the Alaskan Way Viaduct. And it would free up money for better transit and for repairing the dilapidated roads we've already got.

It's your choice. The current plan is to spend the most money ever asked of local taxpayers and still not solve the problem. Or, as you just did, you could try something else.

Danny Westneat's column appears Wednesday and Sunday. Reach him at 206-464-2086 or [email protected].

Copyright © 2007 The Seattle Times Company

Comments

[Josh Strupp]

"So here's my idea: Let's replicate what just happened. We already restrict cars from using Third Avenue downtown at rush hours. Now let's do that on the major freeways."

I really don't know how to address that one. There are so many things that are crazy about that statement I don't know where to begin.

[John Michlig]

Elaborate ....

[Josh Strupp]

First of all, the freeway system is paid for by the same people who drive them everyday....taxpayers. The government has no right to restrict, fine or regulate the taxpayers from using them. Secondly, it's not the government's responsiblity to decide whether or not motorists SHOULD drive on a particular street or through a particular neighborhood or on a particular freeway at a particular time of day. Mr Westneat assumes that the government knows more about how I should get to and from work than I do. This idea is just another attempt at making travel so painful to the motorist, that they will just give up and take the light rail or the bus or the cable car. Metropolitan areas that commute primarily by car will never embrace public transit to and from the suburbs (i.e. Milwaukee).

[John Michlig]

I respectfully disagree with your premise.

You say: "The government has no right to restrict, fine or regulate the taxpayers from using them. Secondly, it's not the government's responsiblity to decide whether or not motorists SHOULD drive on a particular street or through a particular neighborhood or on a particular freeway at a particular time of day."

On the contrary: The government can and does restrict, fine and regulate freeway and road usage. They determine how fast you can go; what weights are legal; how much you should pay per axle; which lanes are open to you as a "car pooler"; even what neighborhoods you can drive through, etc.

[Josh Strupp]

There are differences from my premise and your examples of government regulation. The examples you state have been put in place for safety concerns and reduction of wear and tear on roadways (the car pool lane is an option to motorists not a restriction.) The intention of the author of this article is to restrict motorists for the sole intention of forcing them towards public transportation options, alternative routes, different travel times, etc. That is NOT and never SHOULD BE the function of government. This is very similiar to the ideas of some people that we should tax every gallon of gasoline 2 or 3 or 4 dollars a gallon more than we currently do in order to FORCE motorists into public transportation or car pooling. Want to tax Americans? Fine. Want to tax Americans in order to force them into policy that the government feels is right? That's now how it works.