The new grass-roots effort to put a transportation package before Hillsborough County voters in November faces a tough slog. Voters rejected a similar effort in 2010, and another in 2016 by elected officials never made it from the gate. But the latest initiative shows the growing public demand for a modern transit system and a willingness by private citizens to fill the leadership void. It has a long way to go and plenty of details to consider, but this is a promising effort that finally could be a breakthrough on the region’s top challenge.A citizens group called All For Transportation announced Thursday it will launch a petition drive to put a 1-cent sales tax increase in Hillsborough on the November ballot. Organizers are going the petition route because they see no chance that the Republican-led Hillsborough County Commission will put a transit tax before voters. The commission pulled the plug on a transit referendum in 2016, and organizers said they don’t want to again waste years fashioning a transit package that never makes it to the voters. The group filed its paperwork Friday with the county elections supervisor and has until July 27 to submit the 49,000 signatures needed to get the initiative on the ballot. That’s a tight deadline, but not impossible.Under the plan, the county sales tax would increase to eight cents on the dollar, beginning in 2019, for 30 years. Forty-five percent of the money would go to Hillsborough Area Regional Transit to improve bus service and pay for other mass transit options. The remainder would be split between Hillsborough and its three cities for roads, bridges, sidewalks, intersections and other uses such as routine maintenance. The tax would generate about $280 million per year, and of that, about $126 million would go to HART, or more than three times what the agency currently receives in property tax, its single-biggest revenue source.This is a substantial amount of money that could modernize the region’s transportation system. It could provide a funding base for rapid bus, light rail and other new services, while making roads safer and intersections more efficient. The set-asides for mass transit and roads would still give local governments the flexibility to set their own priorities — spending more for transit or pedestrian safety projects, for example —and the language is forward-looking enough even to accommodate autonomous vehicles and other emerging technologies. More importantly, it seeks to bring a closer link between land use and transportation planning, a big gap in Hillsborough that has fueled the far-flung exurbs. The proposal would include an oversight committee to ensure the money was properly spent.Tampa Mayor Bob Buckhorn gave the effort his early support, and the Greater Tampa Chamber of Commerce said it is "excited" about learning more details. The initiative is being backed by both Republican and Democratic leaders in Tampa. Jeff Vinik, the Tampa Bay Lightning owner who is redeveloping downtown’s channel district, also said he is looking forward "to seeing this effort take shape."It’s early still, and there will be time to examine the details. But it says something about the state of Hillsborough’s transportation system and its elected leaders that private citizens would step up to fill the leadership void and lead an effort to address and the shortcoming that threatens to drag down the entire region. They certainly deserve public support at this formative stage.