The passenger compartment of the 1-series remained stable in the frontal offset test. Dummy readings indicated good protection of the knees and femurs of both the driver and passenger. BMW 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 of the driver was good or adequate. Protection of the rear passenger was good apart from the chest, for which dummy readings of compression indicated weak protection. The car scored maximum points in both side impact tests, with good protection of all critical body areas in both the barrier impact and the more severe pole test. A geometric assessment of the rear seats and head restraints indicated good protection against whiplash injuries in the event of a rear-end collision. Tests on the front seats demonstrated only marginal whiplash protection. The autonomous emergency braking system performed well in all tests of its functionality at the low speeds typical of city driving. However, the points for AEB City were not awarded as good front head restraint performance is a pre-requisite for the additional reward for active safety.  Cars produced since October 2020 have modified front seats and head restraints providing improved whiplash protection.  These seats were tested as part of the assessment of the 2 Series Gran Coupe.  Cars with these front seats would have scored enough in the dynamic whiplash tests for the car to qualify for the AEB City points and the score in adult occupant protection would have been higher, although the star rating would be unchanged.

In the frontal offset and side barrier crash tests, protection of both the 6- and 10-year dummies was good for all critical parts of the body, and the car scored maximum points in this part of the assessment. The front passenger airbag can be disabled to allow a rearward-facing child restraint to be used in that seating position. Clear position is provided to the driver regarding the status of the airbag, and the system was rewarded. All of the restraint types for which the 1-series is designed could be properly installed and accommodated.

The 1-series has an 'active' bonnet. Sensors in the bumper detect when a pedestrian has been struck and actuators lift the bonnet to provide greater clearance to the stiff structures in the engine compartment. BMW showed that the system performed robustly for a variety of pedestrian statures and over a wide range of speeds. Accordingly, the bonnet was tested in its deployed, raised position and protection over its surface was almost entirely good, poor results being recorded only along the base of the windscreen and on the stiff windscreen pillars. The bumper provided predominantly good protection to pedestrians' legs at all test points. Protection of the pelvis was mixed with areas of good and poor protection. The AEB system can detect pedestrians and cyclists as well as other cars. In tests of its response to such vulnerable road users, the system performed well, with collisions avoided or mitigated in all test scenarios.

The 1-series has a seatbelt reminder as standard equipment for the front and rear seats. Lane support helps prevent inadvertent drifting out of lane by warning the driver and gently correcting the vehicle's path. The standard-fit speed assistance system uses a camera to determine the prevailing speed limit and presents this information to the driver, allowing the limiter to be set appropriately. The AEB system performed well in tests of its response to other cars at highway speeds, with collisions avoided or mitigated in all test scenarios.