To retrofit means to add a component or accessory to something that was not there when originally manufactured. Sounds simple enough, at least according to new or proposed state laws. However, when retrofitting safety technology such as seatbelts or crossing arms, there are many considerations that school district leaders need to consider.
The Lone Star State
Texas Senate Bill 546 requires all school buses transporting students to be equipped with lap/shoulder seatbelts by 2029. It expands upon a 2017 law that only applied to buses manufactured after 2018. SB546, which took effect on Sept. 1, tasks school districts with reporting seatbelt status and retrofit costs to the Texas Education Agency.
SB546 does not provide state funding but allows a temporary exemption if retrofit costs are too high, or retrofitting would void the bus manufacturer’s warranty. Districts are required to publicly report the reason for not ordering lap/shoulder seatbelts and estimated retrofit costs. Teri Mapengo, director of transportation for Prosper Independent School District near Dallas, noted that while all 230 school buses in her fleet have lap/shoulder seatbelts, she cautioned other districts to do their homework. At a previous district, she recalled the challenges of retrofitting seatbelts.
The process is harder than specifying a new purchase order. Instead, legacy buses must be taken out of service while retrofit work is conducted. Plus, she said it takes people power and resources to deliver each bus to the facility, transport that driver back to the facility, then arrange for the bus to be picked up once the installations are completed.
“The hard piece is, that you’re going to have to have some of your buses go out of commission,” she said. “So, if you don’t have spare buses to be able to use for operation, then it’s tough.”
She noted that her previous district also encountered seat structure malfunctions when retrofitting. She recalled taping off seat rows to prohibit students from sitting in them due to safety concerns. Those buses had to be sent back again to be fixed.
She noted the metal attachment that secures the seats at the wall flange would break. Seats are also secured at the aisle floor pedestal. Every bus that was retrofitted would
then need to be inspected by the mechanics to determine any deficiencies.
“The biggest thing that I took away was, when you’re going to retrofit your buses, you [need to be] talking with that company [doing the retrofit] and saying, ‘If this were
to happen, how would we get this fixed? And is there a warranty on that work that you guys are doing?’”
Because all Texas school buses manufactured and sold after 2018 should have seatbelts installed at this point, older buses may not be compatible with newer seats. Around 2014, school bus manufacturers offered seating options that allowed standard seatbacks to be upgraded to those with lap/shoulder belts, which is still an option today. Most older buses do not have options for retrofits or upgrades.
“We were having a big issue with that in my previous district, and so it was just having that communication with the company that we were working with, and they ended up still fixing all of those and then figuring out why that was happening,” she said.
In conversations with other Texas transportation directors, she said many are hoping that the law will add a funding element, especially since Texas districts have received less funding than previously.
Forty miles down the road, Jennifer Gardella sits in a very different situation. The director of transportation for Rockwall Independent School District near Austin currently has almost 50 school buses in need of retrofitting, at an estimated cost of nearly $1.5 million. She noted that the cost estimate depends on the school bus model and how the seats are attached.
She, however, also shared concerns about the scope of statewide installs. “If everyone is doing the retrofit, then how will the vendors keep up with repairs and/or getting the buses back for the start of the school year?” she asked, adding that Rockwall ISD doesn’t have extra activity buses or special program buses to be used as replacements.
Retrofit Decisions Not to Be Taken Lightly
“School bus and seat manufacturers rely on specific manufacturing and assembly processes to ensure their vehicles, seating and lap/shoulder seatbelts meet all applicable state and federal safety regulations,” explained Albert Burleigh, vice president of North America Bus Sales at Blue Bird. “School bus makers typically do not sanction or certify compliance of any aftermarket installations or modifications made to the bus that changes the original seating configuration. Therefore, retrofitters need to conduct their own evaluations to ensure full compliance with all safety regulations. They bear full
responsibility.”
A spokesperson for Thomas Built Buses shared a similar sentiment, noting that “school bus seating systems are engineered as an integrated structure that must meet specific safety standards for strength, crash performance, and so on.”
They added that in many cases adding lap/shoulder seatbelts requires replacement seats specifically designed and tested to accommodate those restraints, as well as proper attachment to the bus structure.
“Thomas Built Buses certifies that each vehicle meets all applicable Federal Motor Vehicle Safety Standards at the time it is manufactured but cannot attest to the compliance of items installed after that,” the spokesperson continued.
For buses originally built with convertible seating designed to accommodate future restraint upgrades, Thomas can provide technical guidance, the spokesperson said, adding that school districts and operators “should work closely with qualified vendors and ensure that any retrofit work is properly certified and compliant with all applicable regulations.”
A spokesperson for IC Bus said the process of adding lap/shoulder seatbelts to existing seats involves various considerations with federal seatbelt standards and requirements. IC Bus encourages its customers and operators to consult with their local IC Bus dealer to discuss retrofitting options.
Addressing Other Safety Needs
Meanwhile, Maine lawmakers introduced legislation that would require school buses in the state to have crossing arms mounted on the front of the vehicle and anti-pinch door sensors that detect objects caught in the loading doors. The bill aims to address two safety issues, which resulted in state fatalities within a little over a month span. A 12-year-old was killed in Rockland by their own school bus during drop off in November, and a 5-year-old in Standish was dragged and killed by a bus door in December. The National Transportation Safety Board is investigating the dragging incident.
The bill would apply to all buses regardless of model year, meaning older buses without these systems would need to be retrofitted or replaced. Additionally, school bus drivers who do not activate the crossing arm when students load or unload could lose their school-bus endorsement for up to two years.
Different from Texas, Maine state leaders proposed funding to support the upgrades, about $4.3 million. A school bus mechanic in Maine who requested to remain anonymous shared their district hasn’t started the retrofitting process as it waits to see if there will be funding. The mechanic said the district currently has 50 to 55 school buses in its fleet and all but seven have crossing arms. Those are more straightforward retrofits due to the fact they have already been on buses for many years.
Retrofitting anti-pinch systems onto older buses, the mechanic said, will be harder and more expensive. “Not only do you have to fit a new door mechanism but you have to run a new electrical system and reprogram if not swap out modules to be able to properly operate the system,” he said.
They added a preference that retrofitting be performed in-house to save on labor and overall costs to the district. “If the legislation passes, we are prepared to do what is
needed to meet it,” the mechanic noted. “I haven’t heard any specifics yet, but I know Blue Bird is taking this issue very seriously and is working on a solution to the retrofitting issues of the anti-pinch. Without funding from the state, I believe that a large portion of the entire bus fleet in Maine will be out of service and off the road.”
Andrew Wiseman, sales engineer at anti-pinch sensors manufacturer Mayser USA, said his company is working with Maine very closely on the potential retrofit.
Based on conversations, he said there are 2,000 to 3,000 school buses statewide that would require anti-pinch doors. “We have our partnership with Blue Bird, so we will be working on an aftermarket kit with them in the near future,” he said, adding there are also ongoing discussions with IC Bus and Thomas dealers in Maine on retrofit solutions.
“One of our big unknowns is some of the older buses do not have the necessary [electronic] logic to process an anti-pinch sensor’s signal, so we are also providing a control unit that can be mounted above the door and wired into the main control system, but we are still determining how many of these vehicles need control units at this time.”
He said it would be ideal for Mayser to work with the dealers on the best or recommended installation, and then the bus dealer can disperse this knowledge to school district mechanics on how to install the technology.
Wiseman noted that Mayser’s solution for the Maine retrofit costs around several hundreds of dollars per door, if a control unit is required, with the price being reduced further if the control unit can be omitted. For serial production on new vehicles, the price is “even more affordable for school districts” to implement.
The exact time it takes to perform an installation is still in question. “Putting the actual rubber profiles on the doors is easy and takes only a few minutes,” he said. “The difficult part of installation will be the wiring, as a wire will need to be routed from the door blades, into the compartment above the door, wired into a control unit, and then wired into the rest of the vehicle. Our current estimates are that this will take one- to- two hours per vehicle, but this is a rough estimate. Hopefully, we will gain this knowledge soon when we are testing our solutions with the manufacturers.”
Editor’s Note: As reprinted from the April 2026 issue of School Transportation News.
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