HART looks to replace diesel buses with electric battery buses by 2035 HART looks to replace diesel buses with electric battery buses by 2035 and last updated 2021-04-29 07:48:36-04 HILLSBOROUGH COUNTY, Fla. â The Hillsborough Area Regional Transit Authority is working to replace all of its diesel engine buses with electric battery buses by 2035. The goal is to reduce air pollution across the Tampa Bay area and create more job opportunities. The plan includes three phases. First, HART will replace 74 diesel buses that are ready for replacement within the next two years. Then, in the next...