Tim the Crash-Test Dummy survived 16 bullets that thudded into ballistic glass inches from his head. The shots were fired in a tight pattern by a pair of onrushing Bucks County SWAT team officers simulating an attack on a transit bus operator.

Part of a union agreement reached late last year, SEPTA is adding bulletproof glass compartments for its bus drivers. On Tuesday a group of SWAT officers will fire multiple rounds at the glass to test its durability.

SEPTA is planning to roll out bulletproof glass cockpits on buses this spring to protect drivers. Why it matters: This would likely be a first for any public transportation agency in the U.S., according to the union representing bus operators.

In the wake of the shooting death of a SEPTA bus driver nearly a year and a half ago, the agency will place eight protective shields in its busses in a pilot program to protect drivers.