The Prius Plug-In Hybrid has a standard Secondary Collision Brake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Kona Electric doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.
Both the Prius Plug-In Hybrid and the Kona Electric have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front and rear seatbelt pretensioners, front wheel drive, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning, driver alert monitors and available around view monitors.
Side impacts caused 23% of all road fatalities in 2018, down from 29% in 2003, when the Insurance Institute for Highway Safety introduced its side barrier test. In order to continue improving vehicle safety, the IIHS has started using a more severe side impact test: 37 MPH (up from 31 MPH), with a 4180-pound barrier (up from 3300 pounds). The results of this newly developed test demonstrates that the Toyota Prius Plug-In Hybrid is safer than the Kona Electric:
| 
 | Prius Plug-In Hybrid | Kona Electric | 
| Overall Evaluation | GOOD | GOOD | 
| 
 | Driver Injury Measures | |
| Head/Neck | GOOD | GOOD | 
| Torso | ACCEPTABLE | ACCEPTABLE | 
| Torso Max Deflection | 1.46 in | 1.57 in | 
| Torso Deflection Rate | 9 MPH | 9 MPH | 
| Pelvis | GOOD | ACCEPTABLE | 
| Pelvis Force | 759 lbs. | 915 lbs. | 
| Head Protection | GOOD | GOOD | 
| 
 | Passenger Injury Measures | |
| Head/Neck | GOOD | GOOD | 
| Head Injury Criterion | 246 | 282 | 
| Neck Tension | 45 lbs. | 67 lbs. | 
| Torso | GOOD | ACCEPTABLE | 
| Shoulder Deflection | 1.42 in | 2.09 in | 
| Shoulder Force | 268 lbs. | 335 lbs. | 
| Torso Max Deflection | 1.06 in | 1.61 in | 
| Torso Deflection Rate | 5 MPH | 10 MPH | 
| Pelvis | GOOD | GOOD | 
| Pelvis Force | 692 lbs. | 759 lbs. | 
| Head Protection | GOOD | GOOD | 

