By Dom Nozzi
For any major travel route within or between reasonably healthy cities, it is nearly inevitable that such a route will become congested – particularly during rush hours. This is because cars consume so much space that only a few motorists are needed to congest a road.
How much space do cars consume? On average, a person sitting in a car takes up about 17 times as much space as a person sitting in a chair, and up to 100 times as much space when the car is moving. That is an enormous amount of space, and explains why so many cities are suffering tremendously from the disease I call GIGANTISM. Gigantic streets, gigantic intersections, gigantic parking, and gigantic sprawl are the inevitable result of a form of travel that eats up a huge amount of space. Too many communities have made the mistake of thinking they can provide enough space for these space-hogging cars by building over-sized facilities that destroy a sense of place, among other terrible outcomes.
Over the past century, analysts have learned there is an Iron Law of Traffic Congestion. This inescapable law informs us that you cannot build your way out of congestion. You cannot widen a highway enough to eliminate congested conditions in the long term. Indeed, many studies have confirmed that a wider highway becomes congested about five years after the widening. As the adage says, widening a road to eliminate congestion is like loosening your belt to eliminate obesity.
Widening a highway quickly leads to congestion because in a relatively healthy region or community, there is a great deal of latent demand for travel on that route. When congestion is eased (temporarily, I might add), many who formerly avoided driving the route at rush hour now flock back to driving the route at rush hour. Formerly, these newly-created (induced) motorists were discouraged from driving on the congested road at rush hour due to the inconvenience of congestion. Such people opted to use a different route, travel at times other than rush hour, or opted not to make the car trip. Now, with the newly widened highway, such discouraged motorists are “induced” to return to the highway to enjoy the less congested conditions. Congestion therefore re-appears very quickly.
Studies also show that providing even high quality transit will not ease congestion, as the motorists who leave their cars and use transit instead are merely opening up new highway capacity that induces other motorists to start using the highway. The new space is created by the motorists who are now using transit.
An additional problem that highways face is that when they are free to use, they inevitably attract what are known as “low-value” car trips. That is, a person often rationally decides that it would be acceptable to drive to a shopping center on a major road at rush hour to buy a cup of coffee. Since roads are so terribly expensive to build, maintain, and widen, such trips are not affordable for a community to support with its tax revenues.
Finally, a great many car trips are occurring because motorists are so heavily subsidized. The few user fees we have, such as the gas tax, pay only a small fraction of the total cost to build and maintain our road system. And since nearly all car trips end at a “free” parking spot, motorists are also heavily subsidized when they park. Most of the money for car travel comes instead from such things as sales taxes, property taxes, and income taxes that we ALL pay – even those of us who don’t use a car (or use a car very rarely). For parking, the cost of “free” parking is hidden. How many of us realize that we are paying for the “free” parking by paying a higher cost for groceries, services, and other products purchased in retail centers? Since bicyclists, pedestrians, and transit users, and rare car travelers are also paying these higher costs, those making frequent car trips are, in particular, being subsidized.
Ruinously, like so many other subsidies, subsidizing motorists mean that there are more car trips occurring than would occur normally had the subsidies not been in place. Subsidies encourage many people to make more car trips than they would have otherwise.
Given the above, are there any effective ways to durably reduce congestion over the long term?
The most effective, fair way to reduce congestion over the long term is a toll, whereby the motorist pays each time he or she drives on the road, and pays an amount that is calibrated to keep congestion at bay. As Donald Shoup says about parking, this toll amount is best based on the “Goldilocks” principle. That is, the toll should not be too high, as too few would use a road that the community spent a lot of money to build. The toll should not be too low, otherwise it will be over-used to the point of congestion because it will attract too many “low-value” car trips. Instead, the amount of the toll should be “just right.” An amount that creates a level of traffic that is considered tolerable by the community.
What are the benefits of tolling a highway such as US 36?
First, tolling allows the community to start to create fairness in how much we pay for car travel. By tolling, a higher percentage of the money needed to build and maintain the road is paid by the users – motorists. Without a toll, as I noted above, those not using US 36 at all (or only rarely, or only at non-rush hour times) are paying almost as much as those who regularly drive on US 36. This is patently unfair. Tolling therefore increases fairness by having motorists pay more of their fair share.
Second, tolling is one of the few things – besides a “time tax” such as congestion – that can discourage “low-value” car trips. Again, building a highway that has enough capacity to accommodate low-value car trips is unaffordable.
Third, tolling creates a “willingness to pay” dynamic that an untolled road fails to do. Since some trips are more valuable than other trips, it is important that we create a road system that allows a person to pay if they are willing to do so to avoid congestion. A person that is running late to reach a job interview should have the option of paying a toll to avoid congestion. An untolled road does not provide that desperate person with such an option, and instead offers the same level of access to the road as the person who is making a low-value car trip to buy a cup of coffee. It is clearly unacceptable for a person making a higher value trip to be delayed by a person seeking a cup of coffee. Tolling therefore acknowledges that there are certain trips that are more valuable than others.
Fourth, tolling creates a significant amount of new revenue that can be used to build higher quality bus or rail service (which especially benefits lower-income individuals). The Denver-Boulder region, as well as the State of Colorado, have long had an enormous shortfall in needed transportation revenue due to such factors as a gas tax that is too low (it has not been raised for several decades, despite inflation), and the fact that most revenue comes from sources that ignores how much (or when) a person drives a car. Mostly, these sources are sales tax and property tax. By contrast, user fees are able to account for higher levels of car travel. The new toll revenue can be used to provide more transportation options for lower-income (and other) groups, by dramatically improving transit quality. Without the toll revenue, state and local governments will not have anywhere close to the amount of money needed to provide quality transit in our lifetimes.
Fifth, because free roads and heavily subsidized motorists are artificially induced to travel much more than they would in a more fair system (ie, one that was based on user fees), residents in the Denver-Boulder region are being induced to drive a car excessively. Doing so dramatically increases greenhouse gas (global warming) emissions, fuel consumption, suburban sprawl, strip commercial, and extreme levels of car dependence that significantly degrades the quality of life of the region.
Sixth, untolled roads significantly promote the profits of huge corporations such as oil companies, road builders, automakers, and builders of sprawl housing. Why? Because such free-to-use roads create such high levels of car use that citizens are inevitably compelled to pay a lot of money to such corporations as a necessary part of their subsidized, car dependent lifestyles.
Seventh, by artificially inducing citizens to drive more often due to subsidies, our region is artificially reducing the number of trips that would otherwise be made by walking, bicycling or transit. Why? Because over-providing for car travel creates what economists call a “barrier effect.” The barrier effect is one where non-car travel occurs less often because excessive car dependence makes walking, bicycling and transit use too dangerous or inconvenient.
Eighth, tolling allows the Denver-Boulder region to avoid the failed, ruinous, financially bankrupting path that other parts of the nation have followed. That path is road widening (loosening their belts to eliminate obesity). It is the path that the Colorado Department of Transportation first proposed for US 36: To create a monster highway 10 lanes in size.
Fortunately, wise and tireless efforts by leaders in the region over the past 10 years succeeded in allowing the Denver-Boulder area to avoid that grim, mistaken path. Instead, a much more affordable and effective plan has been adopted: Retain the two free, untolled lanes in each direction, and create a new, tolled (“managed”) lane in each direction that is priced to maintain free-flowing bus rapid transit travel, as well as carpool travel. Free-flowing single-occupant vehicle travel is also provided for, because those willing to pay money to avoid the congestion are able to do so (again, that option does not exist on an untolled road).
Happily, toll revenue from single-occupant vehicle travel will substantially supplement the extremely depleted coffers of our transportation departments, which gives us a near-term ability to provide the quality bus and rail transit we strongly desire.