We know D.C. Get our free newsletter to stay in the know.

Remember that time you waited for a Metro train to arrive in five minutes—the wait displayed on one of those big station screens—but it didn’t come until eight or nine? Remember the time before that… and the other before that?

Which is all a way of saying: Riders frequently complain that their use of public transit is less-than optimal because Metro’s reported wait times don’t always accurately predict when trains will arrive. That difference between appearance and reality may one day change—if documents Metro’s board will consider tomorrow are to be believed.

A report before the board’s Customer Service and Operations Committee says the transit agency is developing a new “key performance indicator” to address riders’ concerns about the gap between Metro’s on-time performance measurement and anecdotal evidence. Today, on-time performance is determined by the wait time between trains, known as headway: If you need to catch a Red Line train during rush hour, one should arrive within three minutes.

“However, customers have expressed a disbelief in the measure because the results often do not match their experiences,” the report explains. “Customers have repeatedly commented that they are more concerned about the overall amount of time it takes to complete a trip and the reality and predictability of their travel time.”

A new pilot program seeks to change that. According to Metro, it will measure both “customer travel time and the percent of customers who are delayed,” making the agency “the first U.S. system to have such a measure.” This new metric could be customized for individual riders who use SmarTrip cards, the report says, allowing them to access personalized travel information: “A bi-product of this effort will be the release of secured travel time data for the public and app developers who will be encouraged to independently build tools for smartphones” and similar tools.

Through ongoing surveys, Metro has found that customers report on-time performance 62 percent of the time; the agency itself reports it 79 percent of the time. Riders cite slow train rides, long waits, crowded platforms, offloaded trains, broken escalators, and other elements among the causes of delays that aren’t reflected in the current metric.

“Staff found that the measure of percentage of customers on time resonates with those surveyed, meets our criteria of conveying the dependability of the trip and magnitude of delay, and is scalable across the system,” the document explains. “This overall measure will be divided into increments that display magnitude of lateness with several sub measures that look at customers late by: less than five minutes, between 5-10 minutes, and 10+ minutes.”

The pilot could one day come to Metrobus, too: “With improvements in on-board passenger counting systems and the growing sophistication of business intelligence tools there may be future opportunities on bus.” (There’s no comparable data for buses now because customer’s don’t have to “tap-out” to get off as they do through Metrorail.)

Meanwhile, Metro-watchers are wondering who will replace Mortimer Downey this year as board chairman: a Virginia businessman, Jim Corcoran, or Ward 2 D.C. Councilmember Jack Evans. Both men sit on the board.

Photo by Darrow Montgomery. Screenshot of graph via Metro report