TAMPA — Hillsborough Area Regional Transit Authority board members got a glimpse Monday of what life could be like with — and without — the estimated $30 million in extra revenue that a proposed half-cent sales tax would bring to the county's bus system.If the new tax is approved next fall, HART would create six new local bus routes, improve service to MacDill Air Force Base and add nine express routes that would make commuting a more realistic option for those looking to ditch their cars.Without the half-cent sales tax, HART could improve — but not expand — service. The agency could extend service hours and increase the frequency of stops. But there would be no new bus routes, no additional park-and-rides and no new maintenance facilities."That's the most important point of the whole discussion: Do you want things to stay the way they are?" said Sandy Murman, a county commissioner and HART board member. "Because that's what happens if we don't go forward."HART senior manager Marco Sandusky briefed the board on the agency's transit development plan, a state-mandated 10-year plan that guides how the agency prioritizes and allocates funding.The plan is very much a work in progress, Sandusky said, and it contains two options: what the agency can do if funding levels remain the same, or what it could accomplish with increased cash flow from sources like a potential sales tax.County leaders are poised to ask voters in November 2016 to approve a half-cent sales tax that would generate $117 million a year. The community transportation plan — known as Go Hillsborough — would devote a quarter of its revenue to HART.If voters pass the referendum, HART wants to be ready with a list of specific improvements and projects it could implement in the first decade of the 30-year tax. This is a deliberate strategy, as politicians hope to avoid the mess of 2010, when voters rejected a similar proposal that lacked specifics.Though the plan won't be made final until HART gathers public input from 10 meetings, that project list could include the following: • Add six local bus routes, three MetroRapid routes that make fewer stops than normal buses, nine HARTFlex zones that provide door-to-door service and five regional Park n Rides.• Expand current commuter express routes to eight trips each morning and evening, up from two, and add nine commuter express routes that connect park-and-ride locations to downtown, MacDill Air Force Base and other counties.• Improve frequency on seven local routes and five HARTFlex zones. Connect Hillsborough's bus system to Pinellas County's bus system via Oldsmar and extend the Route 46 bus line to MacDill Air Force Base.• Make infrastructure improvements, such as buying new buses and adding a new maintenance facility.If voters shoot down the referendum, as they did with attempted 1-cent sales taxes in Pinellas and Polk counties last year and Hillsborough in 2010, HART will proceed with the status quo.The status quo plan aims to increase route frequency, extend service on several routes to include weekends, run all local routes until at least 10 p.m. on weekdays, restructure Route 10 to serve Rocky Point, and add six new van-based routes."We are clearly doing this to answer the question of, 'What does a Go Hillsborough investment look like coming out of HART?' " CEO Katharine Eagan said. "We have an absolute responsibility to educate folks on what that investment can look like if they want to make that choice."That list of proposed improvements will likely change based on public input before it is finalized for the new fiscal year, Eagan said. But the important part is that it is being drafted in conjunction with the county's plans for the potential sales tax revenue.Board members stressed the importance of coordinating with the County Commission to help pass the referendum."When we present this plan, we need to give reasonable expectations," said Kevin Beckner, a county commissioner and HART board member.Murman said it is critical that leaders stress to voters the differences between what can be accomplished under the status quo plan and what sort of impact an additional $30 million can make a year. Communicating those specific projects, she said, will be key to connecting with voters."Know that we are at a critical point now in the conversation about transit and transportation in our community," Eagan said "This is a critical time for HART."Contact Caitlin Johnston at [email protected] or (813) 226-3401. Follow @cljohnst.