Both the Discovery and GLB have child safety locks to prevent children from opening the rear doors. The Discovery 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 GLB’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.
To provide maximum traction and stability on all roads, All-Wheel Drive is standard on the Discovery. But it costs extra on the GLB.
The Discovery’s standard lane departure warning system alerts a temporarily inattentive driver when the vehicle begins to leave its lane and gently nudges the vehicle back towards its lane. A lane departure warning system costs extra on the GLB.
To help make backing out of a parking space safer, the Discovery’s standard rear cross-path warning system uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. The GLB doesn’t offer a cross-path warning system.
Both the Discovery and the GLB have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front and rear seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, blind spot warning systems, rearview cameras and driver alert monitors.
The Land Rover Discovery weighs 974 to 1522 pounds more than the Mercedes GLB. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.