Tredyffrin Township Police Superintendent Andrew Chambers, suspended without pay for allowing his 16-year-old son to drive a township police car in an episode that ended when the teenager crashed the car into a small tree, will retire Dec. 30, township officials said Monday.

Chambers' four-day suspension began Wednesday. He is scheduled to return to work Tuesday.

Township Board of Supervisors Chairman Robert W. Lamina announced the resignation at the board's Monday night meeting, saying he had "mixed emotions" about Chambers' departure.

Lamina said Chambers had decided to leave after "serious reflection" and added that Chambers' decision to retire played no role in determining the punishment the supervisors meted out.

Chambers has served on the Chester County township's police force for nearly 30 years. He has headed the department since 2008.

Contact staff writer Anthony Campisi at 215-854-5015, acampisi@phillynews.com, or @campisia on Twitter.