Leadership Team

Greg Slater serves as the Executive Director & CEO of the Tampa Hillsborough Expressway Authority (THEA), where he leads one of Florida’s most innovative and dynamic transportation agencies. At THEA, he oversees an award-winning system that includes the Selmon Expressway, Meridian Avenue, Brandon Parkway, and the Selmon Greenway, serving nearly 4 million customers annually. He is advancing a $752 million capital program that strengthens regional connectivity, improves daily travel, and enhances system performance, while evolving THEA’s groundbreaking Connected Vehicle Pilot into today’s AI-driven, data-integrated system-of-the-future investments.

With nearly three decades of experience, Slater previously served as Secretary of the Maryland Department of Transportation (MDOT), where he oversaw a complex multimodal network spanning 17,000 lane miles of highways, 2,500 bridges, toll facilities, tunnels, BWI Thurgood Marshall Airport, the Port of Baltimore, motor vehicle services, and statewide transit. 

Widely recognized for his leadership, including honors on the Tampa Bay Business Journal’s Power 100 list, the Top 25 to Watch, and Florida Trend’s Florida 500, Slater is steering THEA with fiscal discipline, community value, and regional impact, all while advancing the agency’s mission of enhancing lives by connecting communities. He is a nationally recognized voice on mobility, transportation technology, and innovative project delivery. 

Amy Lettelleir serves as THEA’s Chief Legal Officer, providing strategic legal, regulatory, and transactional counsel that supports the agency’s capital program, executive leadership, and Board of Directors. At THEA, she plays a central role in developing legal strategies for bond issuances, major procurements, public-private partnership structures, and project delivery methods, while also providing guidance on risk management and policy development. 

She joined THEA in 2017 as Chief Financial Officer, where she oversaw financial operations and helped strengthen the agency’s fiscal position and credit profile before transitioning into her current legal leadership role. With more than 30 years of experience in public finance, municipal law, and infrastructure-related transactions, her career includes advising governments and special districts on complex bond transactions, procurement structures, and project delivery mechanisms.

A member of the Florida Bar for more than 25 years, Lettelleir brings a unique blend of legal depth, business acumen, and public-sector experience to THEA’s executive team. She is a graduate of the International Bridge, Tunnel & Turnpike Association (IBTTA) Leadership Academy and a current member of the IBTTA Board of Directors.

Jeff Seward serves as Chief Financial Officer for THEA, where he directs financial strategy, debt management, capital planning, procurement, and organizational performance. His leadership supports THEA’s ability to deliver a billion-dollar capital program while ensuring strong fiscal stewardship, long-term financial stability, and responsible investment of toll payer revenue.

With more than 30 years of experience across government, private industry, and the military, Jeff brings deep expertise in long-range financial forecasting, credit management, auditing, and enterprise system modernization. At THEA, he has overseen major financial initiatives and process modernization efforts that have contributed to strong credit ratings, a market outlook upgrade, robust reserves, diverse investment strategies, and consistent recognition from the Government Finance Officers Association for excellence in financial reporting. Prior to joining THEA, Jeff served as Chief Executive Officer of the Hillsborough Regional Transit Authority (HART) and Chief Financial Officer of the Sarasota Board of County Commissioners, managing complex budgets, economic development strategies, and financial operations.

Jeff holds a master’s degree in public administration and is a Project Management Professional (PMP) and Six Sigma Black Belt. He is recognized for his strong analytical skills, fiscal discipline, and commitment to financial transparency and accountability.

Gregory Deese is the Director of Operations and Engineering at the Tampa Hillsborough Expressway Authority (THEA), bringing more than 20 years of experience in civil engineering, transportation construction, and infrastructure maintenance. A licensed professional engineer, Deese has dedicated his career to public service, with prior roles at the Florida Department of Transportation (FDOT) and the Manatee County Port Authority.

During his 19-year tenure at FDOT’s Tampa office, Deese led high-profile projects including the Gateway Expressway, Howard Frankland Bridge replacement, and the Tampa Downtown Interchange. He also oversaw the bridge inspection and rehabilitation program, managing preservation work on iconic structures like the Bob Graham Sunshine Skyway Bridge. Deese played a key role in emergency response operations, directing post-hurricane inspections and managing rapid traffic restoration efforts.

Known for his innovative problem-solving and commitment to mentorship, Deese served as project manager for Florida’s first phased design-build project—the Tampa Westshore Interchange—and contributed to several statewide task teams to enhance construction practices. He is also a respected educator, having taught extensively at FDOT’s Construction Academy.

Deese holds bachelor’s and master’s degrees in civil engineering from the University of South Florida, where he first connected with THEA through graduate research on the Reversible Lanes bridge. At THEA, he is focused on advancing operational excellence, infrastructure resiliency, and engineering innovation.