The 3 Series Sedan’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The CT4 doesn’t offer pre-crash pretensioners.
The 3 Series Sedan has a standard PostCrash iBrake, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The CT4 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 3 Series Sedan’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 CT4 doesn’t offer a driver alert monitor.
Both the 3 Series Sedan and the CT4 have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, plastic fuel tanks, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, available all wheel drive, lane departure warning systems, blind spot warning systems, around view monitors and rear cross-path warning.
For its top level performance in all IIHS frontal, side, rear impact and roof-crush tests, and its standard front crash prevention system, the Insurance Institute for Highway Safety grants the 3 Series Sedan the rating of “Top Safety Pick” for 2017, a rating granted to only 231 vehicles tested by the IIHS. The CT4 has not been tested, yet.