Jeff Sims, President
Jeff@trucktrailer.org

Jeff has been with the TTMA since November of 2000 serving 10 years as the Engineering Manager and now President since July 2010. Jeff also spent 13 years in the trucking industry with Watkins Motor Lines in many capacities including, dispatch, sales, supervisor, and terminal manager of the Battle Creek, MI and Manassas, VA terminals. Jeff holds a BS in Transportation and Physical Distribution from Auburn University, War Eagle!

John Freiler, Vice President of Engineering
John@trucktrailer.org

John is in charge of facilitating the work of our Engineering Committee. John got his Bachelor of Engineering in Mechanical Engineering from Stevens Institute of Technology. He worked with the Tank Engineering Committee from 1988 through 2007 as an Associate Member. In 2012, John joined TTMA full time. John and his wife Alison live with their two children in Harpers Ferry WV.

Tamara Halstead, Administrative Manager 
Tamara@trucktrailer.org

Tamara joined TTMA in August 2023. Tamara is a multitalented administrative professional with extensive experience in non-profits, marketing, web design & development, print design, executive assistance, retail, education and meeting planning. A native upstate New Yorker, she resides in Manassas, VA with her husband, James. They are the proud parents of 3 adult children, 2 house rabbits and a parakeet.

Robert Moss, Engineering Manager
Robert@trucktrailer.org

Robert joined TTMA in September 2025 and supports facilitating the work between both the engineering and tank engineering committies. He has an extensive background in rhetoric, project management, and customer service. He loves working with members to provide documentation, information, and support. Robert lives in Winchester, VA, wth his wife, Jordan. They are the loving parents of their daugher, Reagan, and share their home with three pets: Aguero, Oscar, and Eloise.