With summer approaching, we should ask ourselves: Would you rather go to Kennywood for free… With summer approaching, we should ask ourselves: Would you rather go to Kennywood for free but have to wait two hours for every ride?

One advantage of a price system, where people pay for what they use, is that it prevents overcrowding. Kennywood is obviously better off charging money for admission. What’s interesting is that the visitors are also better off when they have to pay.

Pittsburgh can learn from Kennywood. Every day, commuters wait in near-endless lines to get into the city. But if we took tolls for the bridges, tunnels and highways leading into the city, we could raise public funds and save commuters their precious time.

That’s a good idea, but one caveat can make it a great idea. The toll should vary by hour according to how much traffic congestion is on the road at a given time. At rush hour, the toll would be highest. On weekends or other times when it’s the speed limit – not other cars – that limits how fast you drive, there wouldn’t be a charge.

This system is called congestion pricing, which I call CP to save characters. It’s an idea from economists William Vickrey and Maurice Allais, who both won the Nobel Prize.

The justification is that people should pay for inconveniencing others. In the case of road congestion, that’s the delay I cause other drivers when I get on an already crowded road. The problem is that when I get on a crowded road, I only consider my own time wasted in traffic, not the additional time other people will now have to waste because of my choice.

The size of the toll changes because the extent to which additional drivers worsen traffic delays depends on how much traffic is already on the road. If there is one car on the road, and I get on, obviously we can both still go the speed limit. But if I get on an already crowded road, I waste a small piece of every driver’s time. Spread over many drivers, the cumulative inconvenience can be costly, so I ought to pay for it.

The biggest advantage of CP is less congestion: Drivers travel farther in less time. London implemented congestion pricing for a 37 percent increase in average traffic speed. We should care for economic and environmental reasons but also because gridlock is really depressing. Economics Nobel winner Daniel Kahnman found commuting ranks last on people’s scale of activities they enjoy, and short commutes are strongly related to one’s happiness. Like Harvard psychologist Daniel Gilbert explains in the Wall Street Journal, “Driving in traffic is a different kind of hell every day.”

Flexible prices distinguish CP from traditional tolling. A fixed toll probably just lowers the number of people driving into the city. On the other hand, CP varies with congestion, so it encourages people to change when they drive. With traffic spread over time, the flow is more efficient, so the total number of trips into the city doesn’t fall much or might increase: Think how 50 people in a line can walk through a door faster than five people wriggling through at the same time.

When we first hear about traffic lessening, we wonder what those drivers will do instead. That’s because our own imaginations are smaller than the cumulative imaginations of people all familiar with their own situations. We can trust, though, that just as we’re sure a spike in the price of peaches will cause people to eat less peaches – without us knowing what they’ll eat instead – that when commuting costs more, people will choose to commute less.

More people will carpool and use public transit. With time, more people will ride bikes and employers might invest in private shuttles. Over an even longer term, CP can influence where people live and where residential investment goes. For the faithless, these very changes are happening right now from higher gas prices.

Pittsburgh is perfect for CP. Most commuters enter through bridges, tunnels and arteries, where collection is easy. We also have traffic problems, need money and have a well-developed public transit system whose biggest problem is low ridership. Finally, we’re always trying to enhance our image as an innovative, renewed city.

And under a new program, the federal government pays most of the cost for implementing CP reforms. Right now there is a ton of money, because a CP proposal for Manhattan New York’s senate just failed. New York legislators are smarter and know what’s better for Manhattan than Nobel Prize winners and Mayor Michael Bloomberg.

Some reject CP because they’d rather not pay. But the question isn’t whether money or magic will pay for our roads, tunnels and bridges. It’s whether we’ll collect the money through tolls that advance our infrastructure’s purpose and fall on those who use the infrastructure or through taxes that discourage working or spending and fall on each citizen regardless.

If you love Pittsburgh, or even if you just don’t hate it, support congestion pricing. Just remember: “Tax drives, not drinks.”

E-mail Lewis at [email protected].