Mr. D. Scott Barbour has served as a director of Allison Transmission Holdings, Inc. since May 2022. Mr. Barbour serves as the Chief Executive Officer and President of Advanced Drainage Systems, Inc., or ADS, a manufacturer of water management solutions in the stormwater and on-site septic wastewater industries, a position he has held since September 2017. From 1989 until 2016, Mr. Barbour worked for Emerson Electric Co., or Emerson, a global technology and engineering company that provides solutions for customers in industrial, residential and commercial markets, most recently serving as President and Chief Executive Officer of its $4.5 billion Network Power business. During his tenure at Emerson, Mr. Barbour also held several leadership positions including Group Vice President of Emerson Climate Technologies, President, Emerson Climate Technologies Asia Pacific Division, and President, Emerson Climate Technologies Air Conditioning Division. Mr. Barbour received his Bachelor of Science in Mechanical Engineering from Southern Methodist University and his Master of Business Administration from the Owen Graduate School of Management, Vanderbilt University. Mr. Barbour also serves on the board of directors of ADS.