The passenger compartment of the DS 3 Crossback remained stable in the frontal offset test. Dummy readings indicated good protection of the knees and femurs of the driver and passenger. DS showed that a similar level of protection would be provided to occupants of different sizes and to those sitting in different positions. In the full-width rigid barrier test, protection was good or adequate for all critical body areas of both the driver and rear passenger. In both the side barrier impact and the more severe side pole test, protection of all critical body regions was good and the car scored maximum points for this part of the assessment. Tests on the front seats and head restraints demonstrated good protection against whiplash injury in the event of a rear-end collision. A geometric assessment of the rear seats also indicated good whiplash protection. Autonomous emergency braking (AEB), which is available as part of the optional 'Active Safety Brake' pack, performed well in the tests of its functionality at low speeds, at which many whiplash injuries occur.

In the frontal offset test, protection of the 10 year dummy was good or adequate for all critical parts of the body. Dummy measurements of neck tension indicated marginal protection of this body area for the 6 year dummy, with other parts of the body well or adequately protected. The front passenger airbag can be disabled to allow a rearward-facing child restraint to be used in that seating position. Clear information is provided to the driver about the status of the airbag and the system was rewarded. All of the restraint types for which the DS 3 Crossback is designed could be properly installed and accommodated in the car.

The protection provided by the bonnet to the head of a struck pedestrian was predominantly good or marginal, with some areas of poor performance at the base of the windscreen and on the stiff windscreen pillars. The bumper provided good protection to pedestrians' legs and the pelvis area is also well protected. The optional 'Active Safety Brake' pack has an autonomous emergency braking system which responds to pedestrians but not to cyclists. In tests of its response to pedestrians, the system worked well.  A system which responds to cyclists is available, separately from the safety pack and it has not been included in this assessment.

The optional AEB system performed adequately in tests of its response to other vehicles at highway speeds. The DS 3 Crossback has a seatbelt reminder for the front and rear seats. A camera-based system identifies the local speed limit and presents this information to the driver, and allows the speed limiter to be set appropriately. Lane support helps to prevent accidental drifting out of lane and also intervenes more aggressively in certain critical situations.