In the field of ergonomics, “reach envelopes” are an important factor to design products that are user friendly. Specifically regarding vehicle controls, the TGS lever affects important features such as console layout. The standard guideline of SAE is only based on AM 95th percentile hand reach. However, due to various human characteristics and sitting positions of the driver, this guideline cannot satisfy all drivers. Therefore, the goal of this study is to develop an optimal TGS lever envelop based on human characteristics. First, the discomfort regression function is extracted through a discomfort experiment and statistical analysis. Secondly, a validation experiment was conducted to compare the estimated discomfort regression value and the measured discomfort value. In addition, another validation test was performed to enhance the package usability and RAMSIS applicability. The 3D human model which controls the TGS lever was derived according to the input data such as stature and upper arm length etc. The usage of RAMSIS software provided another score labeled the RAMSIS discomfort value which was then compared with the regression and measured values. Finally, there are suggestions to improve package design from the application of this regression function to passenger vehicles.