For months, Dave Grooms tweeted into the void about the delays endemic to his SEPTA commute.

The tweets from Grooms, a self-described "ranter," were at times sharp and laced with anger, but his complaints were legitimate.

After two months of largely unanswered tweets, he finally got a call from SEPTA that seems to have led to improvements on his bus and El commute from Lansdowne to Center City. It took a lot of venting and rage, he said, just to get someone's attention.

"The city's population is growing," he fumed in a recent interview. "Those people with money are going to demand that this stuff work, and you can't be some slack, kicked-back, not-give-a-damn organization."

Grooms isn't the only one who thinks riders lack a voice. There are now two separate efforts in Philadelphia to create a riders union to speak for public transportation users to SEPTA or to elected officials. Though the idea is new to Philadelphia, riders unions have been forming in cities around the country. They give riders influence in decision making, but also are spurred by concerns about inadequate government funding for transportation.

"The way transit is funded is almost entirely regressive," said Beau Horton, assistant secretary at Seattle's six-year-old Transit Riders Union. "A lot of politicians and people who work in departments of transportation don't ride transit that often."

One of the new efforts to advocate for riders in Philadelphia comes from Alex Doty, the former head of the Bicycle Coalition of Greater Philadelphia, which made city cycling a mainstream concern in Philadelphia and played a big role in pushing street safety as a central part of Mayor Kenney's agenda.

The other group seeking to organize riders is 5th Square, an urbanist political action committee that this year lobbied SEPTA, unsuccessfully, to eliminate transfer fees.

Both efforts are embryonic, and organizers say they would be willing to cooperate or merge at some point.

SEPTA already has an independent citizens' advisory committee designed to give a voice to riders, and the Delaware Valley Association of Rail Passengers has acted as the riding public's voice on transit issues, but organizers say a union would be more than a bullhorn for passengers' frustrations. It has the potential to drive policy and establish priorities with SEPTA's board and lawmakers and could pressure Harrisburg on public transportation funding for Southeastern Pennsylvania. Almost half of SEPTA's combined capital and operating budgets, about $1 billion, comes from the state.

SEPTA officials supported the idea of Philadelphians advocating for transit but were wary of an independent organization with its own agenda getting involved in what can be delicate efforts to court lawmakers, said Fran Kelly, who runs SEPTA's public and government affairs operations.

"It starts us-against-them," he said.

Doty said his riders advocacy initiative, Pennsylvanians for Transit, wouldn't necessarily work at counter purposes to SEPTA. He compared what he has in mind to the Bicycle Coalition's relationship with the city's streets department. There are disagreements, but they can cooperate on the overarching goal to make Philadelphia streets safer.

"You can see bike groups in other communities that are just sniping at their transportation department and generally are not making a lot of progress," Doty said. "It's gratifying to say how wrong everything is and be righteous, but it doesn't generally tend to lead to solutions."

The timing for a riders union in Philadelphia is right, transit advocates say. SEPTA is trying to improve Regional Rail's on-time performance and is in the midst of a two-year review of its bus network that could lead to substantial changes. The bus network review, in particular, has the potential to improve service for some communities while reducing it in others. Riders should have a loud and influential voice in that process, said Dena Driscoll, a co-chair for 5th Square.

"It's too early to say what the program would look like," she said of the effort to create a union, "but we definitely see … opportunities to organize bus riders to participate in the bus network reform conversations coming up next year."

This year's budget wrangling in Harrisburg created a scare for SEPTA in September when state Republicans proposed using transportation funds to plug deficits. That would have cost SEPTA $263 million out of its $1.4 billion operating budget, officials there said. Gov. Wolf has said he won't allow transportation funds to be raided, but SEPTA officials live in a state of constant wariness that the state legislature will reduce the funding available for transportation.

"We work to defend ourselves constantly," said Pamela McCormick, SEPTA's director of legislative affairs.

SEPTA receives the lion's share of state transit funding, about 66 percent of $1.3 billion in the last fiscal year, and SEPTA must repeatedly make the case that public transit is critical to an area that generates 41 percent of the state's economic activity.

The five-year-old Riders Alliance in New York City has shown that riders unions can be effective in shaping transit service. Its efforts have led to increased afternoon and weekend service on one of the city's subway lines, pre-tax transit accounts through employers, and improved transportation funding. Those tasks have required engaging with the Metropolitan Transit Authority, city council, and state government in Albany, said Sonia Isard, the organization's membership director.

"We sort of look at transit as a political problem," said Isard, who described her group as relying heavily on face-to-face outreach at subway platforms and bus stops to reach riders. "Without an organized constituency, elected officials don't have the ability to prioritize public transit."

In Seattle, the Transit Riders Union began as an ultimately unsuccessful effort to protect free bus rides in the city's downtown, Morton said. The group was successful, though, in advocating for a low-income fare on King County Metro buses, he said.

New York City's Riders Alliance has 1,000 dues-paying members and about 25,000 connected through social media and a mailing list. Those numbers are dwarfed by the city's eight million transit users, Isard said. Seattle's group also has a small number of dues-paying members, about 250. Both Morton and Isard said, though, that it doesn't take big crowds to sway policy.

"Our philosophy is that you don't need eight million people," Isard said. "You need a small group of very committed, very dogged, and well-prepared advocates."