University of Massachusetts Amherst

Search Google Appliance


Retrofit Seat Belts for Buses Are Going Places Fast

Sundar Krishnamurty


Professor Sundar Krishnamurty and Dr. Doug Eddy from the Center for e-Design at the College of Engineering have designed a Retrofit Seat Belt System that makes it possible to install the safety devices on an estimated 30,000 motor coaches and intercity buses nationwide that currently don’t have them. The seat belts can provide snug protection for bus travelers everywhere, but the retrofits are getting plenty of free play in the media following a recent News Office release. Feature articles quickly appeared in the Greenfield Recorder, the Springfield Republican, MassLive, and on the website of the American Society of Mechanical Engineers (ASME).

The new devices are expected to become commercially available within the next year. The new design of the retrofits will allow owners of buses and motor coaches to install the seat belts for about one third to half of the current cost on existing seats. “We have had a lot of interest from bus manufacturers and bus seat builders on licensing our product,” said Professor Krishnamurty, head of the Mechanical and Industrial Engineering (MIE) Department and the leader of the research team working on the retrofit seat belt. “We are now working with our tech transfer office and others on advancing our project.”

As the UMass press release announced, to help commercialize the new Retrofit Seat Belt System, the National Science Foundation Innovation Corps has awarded $50,000 to the research team led by Krishnamurty. His team includes Eddy, John Collura from the UMass Transportation Center, and Charles and Anne Schewe from Sarah’s Wish Foundation, a nonprofit created by the Schewes after their daughter was killed in an overseas bus crash 20 years ago. The Schewes have been working with Krishnamurty on the concept for more than a decade. Anne Schewe is a co-inventor of the device, and Charles Schewe is an emeritus professor of marketing at UMass Amherst’s Isenberg School of Management.

The market for the seat belts already exists. All new motor coaches manufactured starting in 2016 will be required to have seat belts, but only 20 percent of existing buses have the safety devices, according to the 2013 Motor Coach Census. Federal safety officials say that seat belts with lap and shoulder straps in motor coaches can save lives. For example, seat belts could reduce the risk of fatal injuries by 77 percent in rollover crashes, primarily by preventing occupant ejection on impact.

The MassLive article, written by Diane Lederman, said that 20 years ago “Sara Schewe was killed in a bus crash on her way to the Taj Mahal in India. The Deerfield Academy graduate was participating in a Semester at Sea study abroad program sponsored by the University of Pittsburgh. She was one of 50 students on the bus on the trip that day, and one of four students killed along with three adults. Three others were seriously injured. Schewe at the time was a junior at Georgetown University. Her parents Charles and Anne Schewe believe her daughter's life would have been saved if she had a seat belt to wear.”

According to Lederman, cost has been a factor in the past because new seat belts in buses required that the seats be replaced. But the UMass researchers have designed a system that can be retrofitted. Instead of costing $40,000 to $50,000 to replace seats on buses historically, the retrofit will cost less than $15,000.

"Anybody going through a tragedy always searches for some meaning," Charles Schewe said in the MassLive article. "This (retrofit) represents the embodiment of that meaning."

"I'm delighted,” said Krishnamurty in the same article. “From an engineering point of whose mission is to save lives, it's very satisfying to address a critical need in public transportation.”

Now the mission is to see bus companies install them.

In the ASME Article writer Nancy S. Giges said that UMass MIE students became interested in the seat belt issue about eight years ago after attending a workshop conducted by Sara’s Wish Foundation. A key goal of the organization is to create greater awareness about safety in international transportation and travel, especially in student study abroad programs. The UMass team set out to design a portable seat belt for bus passengers so that a traveler could take it anywhere. While the invention was featured in newspaper articles and TV news shows, it never got off the ground.

“The difference between what we could show as an invention and how we could commercialize it is a common problem,” said Krishnamurty in the ASME story. “We couldn’t find the penetrable market or find a viable way for it to become a business entity. No one wanted to take the next step.”

Refinement and testing continued through the early part of this decade, and the passage of the motorcoach seat belt law breathed new life into the project. Hence, UMass researchers decided to focus on existing buses that could still legally operate without seat belt protection. After meeting with bus companies, the researchers learned that the companies wanted seat belts introduced as part of the structure of the bus, rather than as a portable device. Their reasons included more reliable anchoring and affordability. Those specifications meant that the new seat belts would probably have to be installed without removing and re-installing existing seats.

That’s exactly what the UMass research team has done. In the ASME article, Krishnamurty commented that “We have produced a way to tie the person to the structure of the bus now.”

The retrofit seat belt, designed to meet federal standards, is tied down to the same structural frame in which the seats are now anchored, while the portable seat belt didn’t have such an anchoring point. “The new design is structurally a lot safer,” Krishnamurty added.

The ASME article by Giges said the new retrofit allows for customization based on the design, condition, and various configurations of motor coach seats. Giges wrote that the retrofit seat belt “features a center support typically behind each seat that connects rigidly to the floor via a base plate. That support bears or shares the loads of where the belts are anchored. This maintains the integrity of the existing bus frame structure, according to Krishnamurty.”

As Krishnamurty concluded in the ASME article: “This design is affordable because it is the only known way to add seat belts to existing motor coaches without replacement of all the seats. Furthermore, it will be minimally intrusive and noticeable to passengers. Thus, we can expect many bus owners to be interested in a means to improve the critical safety and comfort of their passengers.” (February 2016)