This study demonstrates the use of an additive fuzzy system to control the velocity and gap of cars in a single lane two-car platoon. A throttle- only controller and a combined throttle and braker controller were tested. Simulation results show that follower cars with a combined brake/ throttle controller can maintain a constant gap when the platoon goes down hills and slows. An adaptive throttle controller uses a neural system to learn the fuzzy rules for different vehicle types.