It's a winter evening. Rush hour. It's dark, and relatively mild for January. But it's raining.
A bus shelter on Green Street in Cambridge is already spilling over with dozens of commuters waiting for a bus. You’re now one of them, waiting in the rain when you see a beacon of hope in the distance — two actually — the large glowing headlights of a bus. Is it your bus? Nope. It’s nobody’s.
In fact it’s empty, and as it approaches, you see the three crushing words across the front: “NOT IN SERVICE.”
Ashley Garrett, of Boston, knows the feeling all too well.
"It enrages me," she said. "It enrages me a lot. A bus will just roll out of the station. No service, even though there are crowds of people."
She sees those dreaded out-of-service busses all the time at Ruggles Station. So do riders waiting for the 86 in Harvard Square and the 111 at Haymarket Station downtown.
I wanted to know why a bus goes out of service, so I met up with MBTA Director of Bus Operations Dave Carney at the bus control center in downtown Boston. He explained that it’s common to see out-of-service buses, especially at locations near the start of routes or the garages that house the buses.
"Typically a bus will be out of service going to the start of its route so there may be as many as 800 that are going out, and then same thing — a number of those will pull back to the garage at the end of their shift, so they’ll see those busses," Carney said.
There are other reasons, too: A mechanical issue or a passenger getting a little bus sick and a cleaning is in order. Then there’s “deadheading.”
Sometimes a single bus serves multiple routes on the same day. Maybe it finishes a run as an 86 at Sullivan Station, but then needs to start its next run as a 99 at Wellington Station.
"We may have that bus what we call 'deadhead' from Sullivan to Wellington, so it will be out of service during that time," Carney said.
As frustrating a sight as an out-of-service bus can be, I learned that there is one thing that riders find far more demoralizing: something I call the “unofficial” out-of-service bus, a bus too full to pick up passengers.
"They'll stop a little bit before it to let people off because there's a stop request, but they won't stop at the bus station," said Frankie Trimble, who takes the 111 from Chelsea to Haymarket each weekday. "They will stop before so we don't try and get on."
Michael Harington experiences the same thing with the 47 bus in Cambridge. "It's very frustrating when you realize you've been waiting for 20 minutes, the bus is late, and you can't get on it because its already so crowded." he said. "Frequently you don't even have the option because the bus will just go by."
These aren’t the acts of rogue bus drivers. The decision to drop passengers off near a stop but not pick any up — or to skip stops altogether — is by design, a deliberate decision by both the bus driver and his or her dispatcher back at the control center.
"There’s a line on the floor of the bus that passengers are not supposed to be in front of. The drivers should be asking people to move back so that they’re behind that line, said Carney. "When they just can’t fit anymore people in, they will stop, call the dispatcher and let them know that they are full."
The dispatcher back at the control center will tell the driver whether they can go “drop-off only.”
Dispatchers are following each bus in real time thanks to onboard GPS trackers. They may also have a driver go drop-off only if they see multiple buses starting to bunch up along a busy route. The idea is to keep the busses spaced out.
It’s a fairly common occurrence along busy routes with a seemingly simple solution: Why not just add more buses?
"The quick answer is we don’t have any," Carney said. "If you go to any one of our bus garages during a rush hour you will find that they are completely empty."
That means all 800 or so working MBTA buses are out on the roadways in and around Boston, traveling along more than 200 different routes — all at the same time.
"It’s a zero sum game," Carney said. "We look to see where the service may not be as well used as in other places, and we will rob Peter to pay Paul."
It’s an unenviable position; that Carney says is as frustrating for him and his team as it is for passengers.
"It really bothers us that we are leaving people behind," he said. "We know where the crowding problems are. We try and fix them as best we can, we just don’t have the resources.
With no cavalry of new buses on the near horizon, Carney does what he can, making some hundred minor scheduling tweaks each year to keep up with the changing needs of changing neighborhoods.
He’d like to do more, like move some stops that he said would save time, but that’s not as easy as it sounds.
"Tip O’Neill says that all politics is local," Carney said. "There’s nothing more political than a bus stop. Everyone has a stake in wanting it where it is, or not wanting it where it is, or not wanting it to go where it should go.
In the meantime, there is one thing that a lot of riders say helps them cut down on wait time: one of the many smartphone apps that essentially offers riders the same GPS location information that the dispatchers have back at the control center. They don’t tell you when a bus goes drop-off only, but most do work pretty well. And they’re just a quick download away. And hey, If you haven’t grabbed one already, maybe it’s something you could do to kill a little time while you’re waiting for your bus.
Want to hear more? Edgar also talked busses with Jim and Margery on Boston Public Radio. Listen here.
If you have something you want the Curiosity Desk to look into, email Edgar.