When there’s a serious traffic accident with injuries, people take comfort in knowing that an ambulance is on the way.

But when the crash involves an ambulance, patients and paramedics are put at risk because ambulance design has not kept pace with developments in vehicle safety.

That’s what happened in January 2014, when an ambulance from Allina Health Emergency Medical Services was hit head-on by an SUV on a snowy night in Buffalo Township. The two paramedics were severely injured and the driver of the SUV died.

“It really set us on a path to say we have to do something different,” said Jeff Czyson, director of operations for Allina’s ambulance service.

The force of the collision drove the ambulance’s steering wheel to the back of the driver’s compartment, leaving the driver with numerous broken bones. The other paramedic, who was attending to the patient, was thrown forward, hitting the front of the back cabin and suffering a traumatic brain injury.

Nationwide, there are about 4,500 ambulance accidents every year, with one-third of them resulting in injury.

After the accident, Allina EMS set out to make its ambulances safer but found that the industry’s designs had changed little since the 1980s. “Compared to the advances in passenger vehicles, it is night and day,” Czyson said.

Instead, Allina EMS decided to design an ambulance of its own.

Casting a wide net, it eventually secured agreements with three manufacturers who developed prototypes that Allina tested in the field. The best elements of each were selected for the final model, which will start appearing in the Allina fleet soon. About half the fleet of 68 ambulances will be replaced with the new version by 2018.

Allina EMS chose a truck chassis that had been tested for crash safety. Initially, they thought they wanted a larger truck base, but soon discovered that posed risks of its own. “Our instinct was to go bigger,” Czyson said. “But a larger truck will kill the other driver.”

The new truck base is also more fuel efficient, meaning it will have lower operating costs.

The back cabin was totally redesigned. In most ambulances, paramedics sit on bench seats that parallel the patient gurney. The only restraints were lap belts, which were impractical because paramedics often had to stand up to grab supplies from cabinets positioned at the top of the cabin.

The new design replaced the bench seats with bucket seats, which are equipped with three-point restraints, or shoulder straps. The seats swivel and lock depending on where the paramedic needs to be. Supplies are placed within arm’s reach along the wall of the cabin in a removable pouch system, originally developed for the military, that can be configured to the needs of the moment.

Allina EMS also switched to a power-driven patient gurney, used by some ambulance services already, that replaces ones that were manually lifted and slid into the back cabin. The system holds the gurney in place more securely, providing more safety in the event of a crash. It also reduces workplace injuries from heavy lifting and cuts the risk to patients by preventing falls.

“We’ve had close calls,” said Curt Weber, an Allina EMS paramedic. “This makes it literally effortless.”

In addition, interior lighting in the back cabin was improved to provide better controls, improved task lighting and better ambient light, which can affect patients who are often highly stressed.

“Our primary job is really to reduce anxiety for the patient,” said Czyson.

Even with the improvements, the new ambulances each cost Allina EMS roughly $165,000 — less than if they had purchased existing models.

“We really wanted to improve safety, ergonomics and economics,” Czyson said.