Looking back on steering systems in more than a hundred years that have passed since the introduction of the automobile, it can be seen that original method of controlling cars pulled by animals such as horses was by reins, and early automobiles had a single push-pull bar (tiller steering). That became the steering wheel, and an indirect steering mechanism by rotating up and down caught on.While the steering wheel is the main type of steering system in use today, the team have developed the Twin Lever Steering (TLS) system controlled mainly by bi-articular muscles, making use of advancements in science and technology and bioengineering to develop based on bioengineering considerations as shown in Fig. 1. The objective of that is to establish the ultimate steering operation system for drivers.In the first report, the authors reported on results found by using race-car prototypes as shown in Fig. 2. Advantages in terms of bioengineering are (1) force can be exerted more easily, (2) steering can be accomplished quickly, (3) positioning can be done accurately, and (4) burden on the driver can be reduced (less fatigue). Advantages in terms of vehicle motion are (1) line-traceability is improved and (2) lap time is improved and steering layout is safe.Herein, creating a TLS system using prototype vehicles based on those on the market and verification test results will further be reported.