In this paper, we propose DECoReS (Degree Expressional Command Reproducing System) that allows a powered wheelchair to travel autonomously through commands that include "degree expressions" depending on particular users and environments. When users control a wheelchair through voice commands, they can sometimes give such orders as "go straight speedily" and "curve to the right widely" to qualify the traveling commands. As these examples illustrate, optional words called "degree expression" are appended to the commands. Because degree expressions are ambiguous, traveling styles described with such expressions are altered depending on the users and environments. DECoReS realizes the travels suited per user by learning degree expressional commands and traveling data from the users. DECoReS also reproduces travels suited for a current environment that a user is about to drive by exacting the data with a map similar to the current environment. Our experiments show that DECoReS can reproduce different travels depending on degree expressional commands, users, and environments.