The way Metro fares are calculated is completely confusing — apparently, even to Metro. Proof comes courtesy of reader Wayde Minami, who commutes from Greenbelt to the Smithsonian stop. He got into the habit of taking a longer stroll to the train on his way home on nice days. So instead of riding the Orange or Blue line to L’Enfant Plaza, he’d walk there to get some exercise and avoid a transfer.

That’s a win-win, right? Except that he noticed these trips of his ended up costing five cents extra. Let me repeat that: Metro charges him more to go a shorter distance. “I know it’s just a nickel more in my case, but [it’s] still annoying in principle,” he told me.

When asked about it, WMATA spokeswoman Cathy Asato wrote in a response, “This appears to be an anomaly and has not been brought to our attention until now… Metrorail fares are based on composite miles, which is a calculation of track mileage and straight-line distance. Accordingly, the composite mileage for a station that is farther from a destination can reasonably have a smaller fare.” Let me repeat that: Metro can charge riders more to go a shorter distance.

I played around with the fare calculator and couldn’t find another case in which a shorter trip to the same destination could cost more, but this is nuts.

And so are all of the other various charges that determine how much an individual trip costs. That’s why the best news about the extensive fare changes proposed for 2013 is that the 20-cent peak-of-the-peak surcharge will disappear, along with a few other extras that lead to mathematical meltdowns. If everything goes as General Manager Richard Sarles hopes, the number of potential fare calculations will shrink from 44,000 to less than 15,000.

The proposed changes — a topic of heated community meetings over the past two weeks — would also increase rail fares across the board by an average of 5 percent. Weirdly, the maximum charge for my daily route, from Union Station to Farragut North, would actually get cheaper (\$2.10 instead of \$2.15). But when I’m traveling at off-peak hours, the price would go up from \$1.60 to \$1.70 (the new minimum charge).

There’s a survey asking riders to weigh in on the proposal (see below). But I think everyone can agree that the new fares should be fair. And that means fixing an anomaly that penalizes a rider for taking a shorter trip.

As for Minami, he’s not letting himself be nickeled-and-dimed. He’s just walking one more stop up the Green Line to Archives. “So I’m getting a little more exercise than before without having to pay extra,” he says.