What does playwright William Inge say about the character Will Masters in Bus Stop?

Will Masters is William Inge's representation of a small-town sheriff. Masters, however, serves beyond that role, as indicated by his name. He is also a deacon in his church, and metes out not only justice but also morality among the townsfolk. He is a respected man and a powerful one, which allows him to command everyone's respect. 

William Inge grew up in the small town of Independence, Kansas and is said to have based Bus Stop, among his other plays, on his small-town upbringing. In small towns like Independence it was not unusual for an uneducated or untrained, but highly-moral and well-respected man to serve in the role of sheriff, or even judge. 

In the play, Masters serves as a mediator between Cherie and Bo. Bo insists that Cherie go off with him and become his wife. However, turned off by Bo's brutish and crude display of sexual desire, she resists this. She appeals to Masters for help when Bo becomes forceful. Masters helps by beating up Bo. This is significant because Bo, it seems, has never been beaten up by another man and prides himself on his physical dominance and ability to tame and control anything that is weaker than himself. The beating forces Bo to respect Cherie. Masters forces Bo to behave himself.

If Bo represents the wild frontier, in which a man's value is determined by his ability to bend nature according to his will, then Will Masters represents a man's transition from the frontier to civilization. Masters is an emblem of constancy in the community, as well as a moral guide who resolves conflict, usually in a peaceable, Christian manner. Yet, he will not hesitate to use violence in instances that he thinks call for it. 

Also, because Bo seeks to have Cherie's hand in marriage, one could argue that Masters stands in as a surrogate father whose job it is to determine Bo's worthiness. He also protects Cherie from a man whom he deems unworthy. 

For more analysis of the play and the character of Will Masters, consult William Inge: Essays and Reminiscences on the Plays and the Man.