For enhanced safety, the front and second-row seat shoulder belts of the Mercedes GLB 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 BMW X1 doesn’t offer pretensioners for its rear seat belts.
The GLB’s optional pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The X1 doesn’t offer pre-crash pretensioners.
For enhanced safety, the front seat shoulder belts of the Mercedes GLB are height-adjustable to accommodate a wide variety of driver and passenger heights. A better fit can prevent injuries and the increased comfort also encourages passengers to buckle up. The BMW X1 doesn’t offer height-adjustable seat belts.
The GLB offers an optional Surround View System to allow the driver to see objects all around the vehicle on a screen. The X1 only offers a rear monitor and front and rear parking sensors that beep or flash a light. That doesn’t help with obstacles to the sides.
The GLB’s blind spot warning system uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them. The X1 doesn’t offer a system to reveal objects in the driver’s blind spots.
Both the GLB and the X1 have standard driver and passenger frontal airbags, front side-impact airbags, driver knee airbags, side-impact head airbags, front wheel drive, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, rearview cameras, available all wheel drive and lane departure warning systems.

