Over 200 people are killed each year when backed over by motor vehicles. The X4 offers an optional Active Park Distance Control that uses rear sensors to monitor for objects to the rear and automatically applies the brakes to prevent a collision. The A4 Allroad doesn’t offer automatic braking for stationary objects directly to the rear.
The X4 has a standard blind spot warning system that uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. A system to reveal vehicles in the A4 Allroad’s blind spot costs extra.
To help make backing out of a parking space safer, the X4 has standard Cross Traffic Warning, helping the driver avoid collisions. Audi charges extra for Rear Cross-Traffic Assist on the A4 Allroad.
The X4’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 A4 Allroad doesn’t offer a driver alert monitor.
Both the X4 and the A4 Allroad 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, all wheel drive, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, post-collision automatic braking systems, daytime running lights, lane departure warning systems, rearview cameras and available around view monitors.