Regarding the Feb. 24 Metro article “Mobility report tells sad story for travelers,” on the latest Urban Mobility Report from the Texas Transportation Institute (TTI).

I comment as an economist who has worked in this field for more than 40 years, including a lengthy stint in the policy office of the Transportation Department. The reported numbers are surely accurate, but there is less here than meets the eye.

For Washington, the TTI reports annual delay in peak periods of 67 hours for the average commuter. The Post presents this as somewhat alarming. But it isn’t. It would be a lot of time if you could use it all in one piece — almost a long weekend. But you can’t use it all in one piece. It comes in many little pieces.

As always, some simple arithmetic is helpful. The average commuter probably goes to work 48 or 49 weeks in a year, allowing for vacations, holidays and some sick time. To make it really easy, let’s round up and call it 50 weeks a year and 70 hours of delay. That gives us 1.4 hours a week. Ten trips in a week, so we have 0.14 hours, or 8.4 minutes, of delay per trip.

Delay is defined as the excess time over what the trip would have taken in uncongested conditions. So our average commute trip is 8.4 minutes longer than it would be with no congestion. Doesn’t sound so bad, does it? Yes, that bit of time does add up over the year, and you get to big numbers for fuel consumption, travel time and so forth. And, yes, there are surely stretches of highway in the area where increased capacity would be a good investment.

But auto travel in peak periods is always slower than at other times. This is not “extra” time or “extra” fuel consumption; it is just part of the normal cost of getting everyone to work in the ways that suit them best. It is not, as the headline suggested, a “sad” story; it’s everyday life in the big city.

Urban traffic congestion was with us in ancient Rome, and it still is.

Eric W. Beshers, Jefferson