Hub got their wheels turning

So when Harrelson joined Google as an engineer almost two decades later and saw a demo version of Google Maps that calculated driving and walking directions, he was struck by what was missing from the program: public transportation.

“That Franklin Line was the first train I rode. It stayed with me,’’ said Harrelson, who works at Google’s headquarters in Mountain View, Calif.

Harrelson started talking to colleagues inside Google about how public transit services could be incorporated into what Google offers. And before long he had a team of transportation enthusiasts eager to help him, among them other former Bostonians. It was these young engineers - all with experiences riding the T - who ultimately shaped the Web tool now available in more than 400 cities around the world, including, as of 10 days ago, Boston: Google Transit.

Fully integrated into Google Maps in 2007, Google Transit helps a traveler plan routes via train, bus, and boat, including walking directions to stations and bus stops. It hinges on having local transit agencies, in Boston’s case, the Massachusetts Bay Transportation Authority, provide their own data: precise distances, predicted arrival times, meticulously plotted locations for stops and stations. Google then processes the data to create an interactive map that informs travelers of upcoming departure times and updates about delays and service changes.

Though a number of major cities - including New York and Chicago - joined Google Transit months or even years ago, the MBTA is a relative latecomer to the project, and Bostonians, never known for their patience, were not happy waiting. A Facebook group called “Put the MBTA on Google Transit!!!’’ was formed in February, and has 1,500 members.

“Until recently, the MBTA had no good way to convert our data into Google’s format,’’ said Lydia Rivera, an MBTA spokeswoman. “The MBTA had to do a lot of work to make this happen and ensure that the data is as user-friendly as possible.’’

One of the Google colleagues who joined Harrelson as he developed Google Transit was another engineer, Joe Hughes, who had spent several years in Somerville before he came to the company. He could never decide which bus stop to choose when heading to downtown Boston because he never knew which bus would be coming first. Frustrated by the limitations of the MBTA’s Trip Planner online - you can’t click on train or bus stops to see when the next departures are, for instance - he took matters into his own hands and created a mash-up that fused Google Maps with the trip planner. But the difficulty of acquiring transit data was his biggest limitation.

“As a developer in a bedroom in Somerville, the MBTA would not give me the time of day,’’ Hughes said. As a result, he spent hours extracting data from PDFs on the T’s website.

When he went to work at Google in Mountain View in 2005, he devoted time to the nascent Google Transit. “If there wasn’t a project like that in place, I was going to start it,’’ he said. Like Harrelson and others, he took advantage of a perk the company offered called the “20 percent project,’’ which allows employees to spend 20 percent of their work time brainstorming and tinkering with ideas unrelated to their daily responsibilities.

For about a half-hour every day, Hughes pored over transit data and created software that would check it for accuracy.

Google Transit debuted in Google Labs, a website where the company demonstrates products for the public that aren’t ready to be formally launched. Portland, Ore., was the first city to join, and as more cities shared their data, the initial vision evolved: train station icons became clickable as in Hughes’s MBTA mash-up, opening a bubble containing departure times.

A team of Google cars equipped with 360-degree cameras was dispatched to drive to every bus and subway stop and train station in participating cities to take photographs for the “Street View’’ option. The hardest part, Hughes said, was persuading wary agencies to participate; some did not want to deal with double-checking their data or feared that Google Transit would compete with their own websites.

Tom Sly, who negotiated with transit agencies as a member of Google’s New Business Development Team, lived in Boston from 1996 to 2006.

“From the beginning,’’ he said, “Boston was one of the cities I was most eager to bring on board.’’

As the Red Line lurched and heaved on its way to the Google offices in Kendall Square last week, Steve Vinter, Google’s local engineering director, leaned on a pole inside the train and watched Boston’s skyline outside the window. “We all have various stories and memories about public transportation,’’ he said. “It can shape your perspective on a city.’’