New Bridge Might Not Ease Rush Hour Congestion

Have you ever tried to get through downtown Saint Louis during rush hour? How about before or after a Cards game? If you have, you know it can take quite some time to get from one side of the Mississippi to the other. A stalled car or accident snarls traffic for miles. This type of experience may have you agreeing with proposals to spend hundreds of millions of taxpayer dollars on a new bridge connecting Missouri and Illinois. Before committing taxpayer funds, however, we should rethink the situation. Do we really need that new bridge?

A basic idea in economics is that individuals respond to incentives. If the price of strawberries rises, people buy fewer of them. This same insight applies to commuters. Right now, some people avoid commuting in congested areas because of the time and hassle. If we reduce congestion by building a new bridge, that might just cause more people to take to the roadways.

Reducing the time it takes to commute in and out of Saint Louis could induce those currently using mass transit or ride-share programs to start driving again. Solving the current mess could have the unintended consequence of inducing more traffic entering and leaving St. Louis. And this might just further jam up the connecting roadways. Would building the bridge create a need to further widen I-55 and I-70?

It wouldn’t be the first time. Current traffic flows on the Poplar Street Bridge are significantly greater than engineers estimated when the bridge was constructed. We know that because if they had gotten it right, we wouldn’t need the new bridge. Do we know that their projections this time are any more accurate?

It might be worthwhile to turn the current bridge debate on its head: Instead of finding ways to increase capacity, what if we looked for ways to decrease congestion by reducing the number of cars on the road? Rising gasoline prices are significantly increasing commuting costs. Add to that the cost of sitting in a traffic jam and commuters might begin to alter their behavior. Just think: If rush hour commuters simply doubled the average number of passengers in a car—from one to two—the number of vehicles crossing the bridge would be sliced in half. Commuters create congestion for other drivers on the bridge because they do not bear the full costs of their commuting decisions. The bottom line is that rush hour drivers use up too much scarce bridge space because they don’t pay the real cost.

One way to bring supply in line with demand is to charge commuters for the valuable rush-hour capacity they use. Charging a user fee (a toll) on commuters who use the bridge during rush hour is one way to efficiently price the use of limited space on roads and bridges. And a toll system is fair: Heavy users pay the higher price. To those who argue that toll booths would create more traffic problems, available easy-pass systems can significantly reduce the hassles associated with paying tolls.

Increasing commuting costs by charging congestion fees might lead cost-conscious drivers to take other, less congested routes or travel at non-peak times. Think of it. Carpooling might become more popular.

Establishing a system of user fees is the best means available to efficiently price commuting. If a price system works for movie tickets, electricity, and seats at Busch Stadium, why not for space on the bridge during rush hour?

R.W. Hafer is the chairman of the Department of Economics and Finance at Southern Illinois University Edwardsville.