MBTA service problems and fiscal dilemmas have commanded significant public attention, but a new report says the regional transit authorities that provided 19 million bus and shuttle rides in 2021 lack connectivity and a “funding bedrock.”

The report, released Tuesday, concluded that while regional transit providers “enable a remarkable amount of mobility across Massachusetts,” some towns are not even served by the 15 regional transit authorities, there’s “little coordination” across RTA districts, and communities within RTA zones are not even guaranteed a certain level of service. The fiscal year 2025 budget the Senate will debate next week proposes to eliminate fares for all RTA rides statewide.

“The state’s current approach to regional bus and shuttle service is fragmented and incomplete, particularly in rural areas,” the report said. “The funding mechanism for regional transit lacks transparency, is overly reliant on local contributions relative to the MBTA, and does not adequately account for issues of regional, rural or economic equity.”

The report was conducted by the Tufts University Center for State Policy Analysis and commissioned by the Quaboag Connector, a micro-transit initiative led by the Quaboag Valley Community Development Corporation and the town of Ware. It was funded by the Health Foundation of Central Massachusetts through a Synergy Initiative grant for the Quaboag Connector.

Researchers found that municipalities served by the MBTA contribute 8% of the transit authority’s operating expenses while cities and towns served by RTAs contribute about 20% of operating costs. Beyond local sources, the state provides about 40% of RTA operating expenses and other sources, federal aid 23% and fares just over 14%.

The report calls for government officials to increase funding for RTAs, reassess the way funds are distributed, and incentivize service expansions to give underserved populations more travel options.

“While it is widely acknowledged that the MBTA has been consistently underfunded, it can at least rely on a consistent pool of revenue, namely a fixed portion of the state sales tax,” the report said. “Regional transit providers have no such funding bedrock to rely on, only the vicissitudes of the annual budget process.”