Important Information Regarding Parking Brake Interlock

Check here for the latest updates regarding the Parking Brake Interlock feature on Thomas school buses.


Sonny Merryman Inc. has completed installation of the parking brake interlock feature on all Thomas buses operating in Virginia.

VDOE is continuing to track the brake interlock installation progress of all other manufacturer’s affected public school buses.

Read more here.


The Virginia Department of Education has approved our action plan for bringing all impacted Thomas buses currently operating in Virginia into compliance. You can view the plan here.

update: Monday, May 22 at 11:00 AM

We are currently developing a comprehensive plan to install the parking brake interlock feature on all impacted Thomas buses in your fleet. Delivery of the needed components is expected in mid- to late-June.

We understand the importance of bringing all of your buses into compliance as soon as possible—ideally before school start in the fall. We assure you we will make every effort to meet this target.

A detailed plan of action for bringing all Thomas buses into compliance is forthcoming this week. We will be certain to share the plan with you and will continue to keep you up-to-date of developments concerning this situation. Thank you for your ongoing cooperation and support.

Thursday, May 18 at 4:08 PM

It has come to our attention numerous Virginia school buses have been delivered in recent years that are not equipped with the parking brake interlock function as required by Virginia Department of Education school bus specifications (see below). Your school district may have buses in service that may not be in compliance. School buses equipped with wheelchair lifts and Type A buses are not affected and meet required specifications. Any new Thomas bus delivered after May 12, 2017 will be equipped with the parking brake interlock feature.

Our service team has developed a fully compliant corrective procedure, which has been verified and approved by engineers at both Freightliner Custom Chassis and Thomas Built Buses. We are currently sourcing the required components. Once the componentry is available, we will be contacting school divisions impacted by this issue to implement an action plan for installation of the parking brake interlock function.

We deeply regret this unfortunate oversight. Sonny Merryman Inc. stands ready to work diligently with you and your pupil transportation staff to ensure all Thomas buses are 100 percent DOE compliant quickly and efficiently. Our 50 year commitment to student safety and quality customer support is stronger than ever and will never be compromised. We sincerely value our long-time partnership with you – and, please rest assured, we are on this!

Virginia School Bus Specification: Parking Brake Interlock
Automatic transmissions incorporating a parking pawl shall have a transmission shifter interlock controlled by the application of the service brake to prohibit accidental engagement of the transmission. All nonparking pawl transmissions shall incorporate a park brake interlock that requires the service brake to be applied to allow release of the parking brake.