November 27, 1989
"Taking a Toll - Rush Hour Bridge Fees should be Increased"
San Jose Mercury News
By Timothy Taylor
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I COMMUTE across the Dumbarton Bridge most days, which has allowed me to become a more contemplative person.

Why was the delay at the bridge so long? Were the tollbooths the source of the delay? Was it the merge right after the toll plaza, where six lanes combined into two? Was it the lack of ways to exit onto University or Willow on the other side of the bridge?

So many possibilities. So much time every day to consider each alternative. But times have been changing on the Dumbarton since the earthquake last month. Until the Bay Bridge reopened last week, tolls weren't charged on the Dumbarton during morning and afternoon commute hours. The traffic lanes have been re-striped so that the bridge is now three lanes each way, instead of two. One of the extra lanes is a "diamond" lane for car pools of three or more. The bridge approaches and exits have been streamlined.

I owe flowers and chocolate to somebody at Caltrans for the physical changes to the Dumbarton; they have surely made my life easier. But even with these changes, the bridge is either jammed or hovering on the edge of a jam almost every morning and evening. And like the rest of the transportation grid in the Bay Area, the Dumbarton is only going to get more congested.

Not much more can be done to have the bridge carry more traffic at one time, so it's time to think about providing incentives for the traffic to spread out over more times. Adjustable bridge tolls would be one useful step.

The idea of using bridge tolls to reduce congestion seems more controversial than it should be; many people subscribe to a misguided code of fairness which holds that every car should be charged the same toll, since every car imposes roughly the same wear-and-tear on the bridge. But that view considers only part of the picture.

During the morning rush, no car is an island complete unto itself. A driver who commutes across the Dumbarton during the morning traffic jam helps to impose a costly delay on all the other drivers in line. If the time of the average Dumbarton commuter is worth $12 an hour (probably a conservative estimate) then waiting for 20 minutes imposes a cost of $4.

It is not sensible to set bridge tolls so that commuters often end up spending $4 worth of time so that they can pay $1 at the tollbooth. Instead, tolls should be set to reflect and reduce these costs of congestion. For example, start by doubling the tolls on every bridge in the Bay Area during the morning and afternoon rush. (The rush hours might be determined by the hours that traffic actually backed up during the previous three months.) In addition, charge these higher tolls for cars going both directions across the bridges.

However, cut the toll in half for cars with two people; after all, they are imposing only half the congestion. Those who drive three or more in a car could drive free, whether a particular bridge has diamond lanes or not. During all non-rush hours, the toll should be very low or nonexistent for everyone. After all, cars don't impose any congestion cost by taking the bridge at 1:30 in the a.m. or the p.m., and they should not be charged as if they do.

After some tinkering with the dollar amounts, these variable tolls could bring in just as much money as the current system, while providing an incentive to reduce bridge congestion.

Even though I usually commute alone and would often get stuck for the higher toll, I'd take this system in a minute. Sometimes I'd leave early or late and miss the higher toll. When I couldn't stagger my commute, I'd pay up, but I wouldn't have to wait as long. As other drivers responded in this way, the rush-hour would spread itself out.

Don't expect this proposal to be popular. What we commuters really want, of course, is a system that gets everyone else into car pools and buses so that the road is clear and we can drive on a clear road by ourselves whenever we want to. Personally, I had some of the best commutes of my life the week after the earthquake, with so many people staying home or taking other forms of transportation, and no rush-hour tolls being charged on the bridge. But over the long haul, giving rush-hour commuters a free ride (as was done during the month after the earthquake) was simply illogical; it gave everyone an economic incentive to move their commute to the rush hour.

If the Bay area is serious about avoiding traffic congestion on its bridges and serious about encouraging ride-sharing and public transit and staggered job schedules, then gentle persuasion and diamond lanes will not be enough. The strange truth is that the incentive to use commute alternatives is highest when the bridge (or the road) is already congested, which is the problem we are trying to avoid.

Charging a higher bridge toll during rush hours is perfectly fair, because it reflects the costs that rush-hour drivers impose on others. More important, paying real money is a real incentive to avoid jamming the transportation grid in the first place.

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