Photo by cstein96.

This morning, we learned that WMATA was planning on installing public information displays — kind of like the ones that tell you how soon your train is coming — in dozens of bus shelters around the region. It sounds like a really good idea, right? After all, not all of us have access to a smartphone or the patience necessary to dial the somewhat painful automated system which lets passengers know when the next shuttle will arrive.

Of course, the one big issue with the plan is simple: there’s a good chunk of the time when Next Bus — the real time monitoring system which the new PIDs will draw from — is inaccurate.

Now we know the reason for all those ghost buses: at a board meeting today, WMATA officials discussed how around 15 percent of its bus fleet doesn’t have the appropriate GPS technology that’s necessary to accurately track its location, and hence, provide an estimated real time arrival prediction. WMATA has plans to upgrade the system, including quadrupling the frequency with which the system refreshes its location data and getting GPS technology in all of its buses by 2013.

But until then, we’ll just have to accept that around three times out of four, those brand new signs — scheduled to start being installed early next year — might be showing a bus that doesn’t exist.