For enhanced safety, the front and rear seat shoulder belts of the Volvo S60 have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The Infiniti Q50 doesn’t offer pretensioners for its rear seat belts.
Both the S60 and Q50 have child safety locks to prevent children from opening the rear doors. The S60 Plus/Ultra has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The Q50’s child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.
In the past twenty years hundreds of infants and young children have died after being left in vehicles, usually by accident. When turning the vehicle off, drivers of the S60 are reminded to check the back seat if they opened the rear door before starting out. The Q50 doesn’t offer a back seat reminder.
The Volvo S60 has a standard driver’s side knee airbag mounted low on the dashboard. The knee airbag helps prevent the driver from sliding under the seatbelts or the main frontal airbag; this keeps the driver better positioned during a collision for maximum protection. A knee airbag also helps keep the legs from striking the dashboard, preventing knee and leg injuries in the case of a serious frontal collision. The Q50 doesn’t offer knee airbags.
The S60 has a standard Whiplash Protection System (WHIPS), which use a specially designed seat to protect the driver and front passenger from whiplash. During a rear-end collision, the WHIPS allows the backrest to travel backwards to cushion the occupants and the headrests move forward to prevent neck and spine injuries. At the same time the pretensioning seatbelts fire, removing slack from the belts. The Q50 doesn’t offer a whiplash protection system.
The S60 has standard Post-impact braking, which automatically apply the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Q50 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.
The S60’s driver alert monitor detects an inattentive driver then sounds a warning and suggests a break. According to the NHTSA, drivers who fall asleep cause about 100,000 crashes and 1500 deaths a year. The Q50 doesn’t offer a driver alert monitor.
Both the S60 and the Q50 have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, 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, available all wheel drive and around view monitors.