The U.S. Department of Transportation (DOT) John A. Volpe National Transportation Systems Center, under the direction of the DOT’s Federal Railroad Administration (FRA), Office of Research, Development and Technology, studied the effects of the implementation of quiet zones on trespass accidents along the national rail network. This study focused on 333 quiet zones established between 6/1/2012 and 5/31/2018. Trespass casualties that occurred within the 333 quiet zones were compared before and after the establishment of the quiet zones. Trespass casualties in quiet zones with 2 and 3 years of observable accident data increased from 28 before to 40 after and from 39 before to 47 after the establishment of the quiet zones, respectively. However, trespass casualties in quiet zones with 1 year of observable accident data decreased from 19 before to 17 after the establishment. There was no statistically significant difference in trespass casualties before and after the establishment of the quiet zones for all three observable periods.