Who thought Green Line trolleys driving on the road was a good idea?

Charlie on the MTA was doomed to ride forever ‘neath the streets of Boston. But for today’s Green Line riders, the trouble usually starts above ground.

Coasting along street-level tracks for most of the way, the Green Line’s trolleys often find themselves competing with Greater Boston traffic — sometimes with disastrous results. There are even a couple parts of the Green Line where drivers might see a train come puttering up behind them in mixed traffic (looking at you, E Branch).

So, why is the Green Line largely street-level? And who thought it was a good idea for trains to share the road with cars?

To answer those questions, Boston.com consulted the MBTA and dove into the city’s transit history with Bradley Clarke, president of the Boston Street Railway Association and author of several books on transit in Boston and Massachusetts. 

Novel beginnings

The explanation starts at an obvious point: The Green Line’s origins trace back to the streetcar lines that once blanketed Greater Boston. 

“What’s running on the Green Line today is the same type of principle that was on the Green Line — then called the Tremont Street subway — 100 years ago and, in fact, what was run with horsecars as early as the mid-1850s,” Clarke explained. 

At one point, he said, Massachusetts had the densest network of streetcar lines in the entire country; streetcar tracks could be found on many major roadways throughout the Boston area.

“The system was designed for street-level tracks because that’s what was there to begin with,” Clarke explained.

“There was no need for tunnels or elevated lines in the earliest days,” he continued. “But what happened was streetcars themselves became an important transportation mode. And more and more lines from more and more places started to be built. They all came together in the city, and where they came together, you suddenly had traffic jams of streetcars.”

So in 1895, state and city leaders created the Boston Transit Commission, tasked with building America’s first subway. The Tremont Street subway opened to the public on Sept. 1, 1897, with the original segment running between the Public Garden and Park Street.

“The whole point of the subway was to get heavy, dense streetcar traffic off the street and underground so that the remaining horses, carriages, omnibuses, early motorcars, and so on had a little more space to operate,” Clarke said. 

The tunnels made sense downtown, where congestion was heavy. Further out, however, Clarke noted that the traffic was far less dense in those early days.

He explained that it was common to see streetcars sharing the roads with carriages and automobiles up until the late 1940s, “but there was a steady trend toward getting them off the street wherever possible” — a stance made clear in a 1947 state commission report on rapid transit in Greater Boston.

It’s one reason why the streetcar lines that had reservations — dedicated space away from auto traffic — were able to last, he explained. Beyond that, each Green Line branch has its own history, purpose, and story of survival, according to Clarke. 

“It’s really quite tricky to generalize about this stuff,” he said. “Almost every one of these lines has a raison d’être — a reason to be — and it always is quite explicit about the line.” 

Automobiles exploded in popularity in the first half of the 20th century, and buses gradually replaced some streetcar lines (the Green Line’s dearly departed A Branch is one of the later and more notable examples). 

By the 1960s, the streetcar lines were whittled down to their current lineup: The B, C, D, and E branches of the Green Line, plus the Mattapan Line. 

The Green Line’s quirky features

Today, the Green Line is the only MBTA line where transit vehicles operate alongside public mixed traffic, T spokesperson Lisa Battiston told Boston.com in an email last month. 

Once common for streetcars, street-running tracks — tracks not segregated from car traffic — have long since faded in popularity. In Boston, however, they can still be found on certain parts of the Green Line, namely the E Branch from Brigham Circle to Heath Street.

“That line is an anomaly, and it remains because the local residents like the one-seat ride,” Clarke said. “When they get to the subway, they continue on and get off downtown where they intended to go.”

Non-passenger street-running tracks can also be found near the Reservoir carhouse at Cleveland Circle, running up Chestnut Hill Avenue to the B Branch and crossing Beacon Street to the C Branch. 

And yes, running trolleys alongside traffic can pose some “unique” challenges, Battiston acknowledged, citing intersections where cars, bicycles, and pedestrians are able to cross the tracks.

While some issues — like car accidents — are out of the MBTA’s control, Battiston said traffic signals are one challenge that the T is actively tackling with Transit Signal Priority, which gives preference to public transit and allows trolleys to travel faster through intersections.

But is it ever nerve-wracking to drive the Green Line in mixed traffic? 

“I’d be lying if I said no,” said Scott Page, an MBTA streetcar operator who now serves as the Green Line delegate for the Boston Carmen’s Union Local 589. He’s driven on the Mattapan Line and all the Green Line branches, looking back on the experience as “the best job I ever had.”

According to Page, the segment between Heath Street and Brigham Circle is often the one streetcar operators fear the most when they’re fresh out of training. 

“It’s almost like playing Tetris, but the trolley is fixed. When you’re operating the streetcar, it’s on a fixed course, and you have to know all of your clearances,” Page said.

That involves keeping an eye on stopping distances, traffic lights, potential obstacles, and the traffic in adjacent lanes, he explained. And it can get especially tricky come late August and early September, when Boston’s streets are flooded with moving trucks. 

But Page, who grew up in the Mission Hill and Brookline area, said he has a soft spot for the Huntington Avenue segment of the E Branch. 

“I had a mentor on the job who … was sort of old-school, but his expression was: ‘This line separates the boys from the men,’” he said. “To that extent, it was sort of like, ‘OK, can I master this portion?’ And once you do, … it becomes second nature.”