form of an audio alert, visual pop-up display, or other warning alert. Intelligent speed adaptation or intelligent speed advice (ISA) assists drivers with compliance to the speed limit. They take in information of the vehicle's position and notify the driver when they are not enforcing the speed limit. Some ISA systems allow the vehicle to adjust its speed to adhere to the relative speed limit. Other ISA systems only warn the driver when they are going over the speed limit and leave it up to the driver to enforce the speed limit or not. Intersection assistants use two radar sensors in the front bumper and sides of the car to monitor if there are any oncoming cars at intersections, highway exits, or car parks. This system alerts the driver of any upcoming traffic from the vehicle's sides and can enact the vehicle's emergency braking system to prevent the collision. Lane departure warning system (LDW) alerts the driver when they partially merge into a lane without using their turn signals. An LDW system uses cameras to monitor lane markings to determine if the driver unintentionally begins to drift. This system does not take control of the vehicle to help sway the car back into the safety zone but instead sends an audio or visual alert to the driver. Parking sensors can scan the vehicle's surroundings for objects when the driver initiates parking. Audio warnings can notify the driver of the distance between the vehicle and its surrounding objects. Typically, the faster the audio warnings are issued, the closer the vehicle is getting to the object. These sensors may not detect objects closer to the ground, such as parking stops, which is why parking sensors typically work alongside backup cameras to assist the driver when reversing into a parking spot. Tire pressure monitoring determine when the tire pressure is outside the normal inflation pressure range. The driver can monitor the tire pressure and is notified when there is a sudden drop through a pictogram display, gauge, or low-pressure warning signal. Vibrating seat warnings alert the driver of danger. GM's Cadillacs have offered vibrating seat warnings since the 2013 Cadillac ATS. If the driver begins drifting out of the traveling lane of a highway, the seat vibrates in the direction of the drift, warning the driver of danger. The safety alert seat also provides a vibrating pulse on both sides of the seat