How Nissan’s Driver Assist Tech Reduces Traffic Jams
▼ Summary
– CCM uses a lead car to send information to following CCM-equipped cars, allowing them to maintain a 30-60 second distance and decelerate gently to prevent traffic jams.
– The system operates via embedded LTE modems and Nissan’s cloud, rather than DSRC, and is described as “mixed autonomy” with both controlled and human-driven vehicles.
– Nissan balanced system parameters to address the issue of other drivers cutting in when following distances are too large, which can cause deceleration.
– Simulations show that CCM benefits increase with higher penetration rates, with noticeable results at around 4-5% of vehicles using the system.
– Future refinements may include providing drivers with feedback on why the car is slowing and potentially licensing CCM to other automakers.
Nissan’s innovative driver assistance technology offers a promising solution for reducing traffic congestion by addressing the root causes of stop-and-go traffic patterns. Their Cooperative Cruise Control (CCM) system represents a significant shift from traditional adaptive cruise control, focusing on communication between vehicles rather than relying solely on individual car sensors.
This system operates by designating a lead vehicle as a “probe” that transmits real-time information to other CCM-equipped cars further back in traffic. Even with non-equipped vehicles between them, these connected cars can maintain optimal spacing, typically between 30 and 60 seconds apart. When the lead vehicle detects slowing conditions ahead, the following vehicles receive advance warning and can gradually reduce their speed rather than braking abruptly. This smooth deceleration pattern prevents the concertina effect that typically occurs when human drivers react suddenly to brake lights, which often amplifies into full traffic jams.
Jerry Chou, a senior researcher at Nissan’s Silicon Valley center, describes the approach as “mixed autonomy,” blending controlled vehicles with regular human-driven traffic. Unlike some systems that require dedicated short-range communications, CCM utilizes existing LTE modems built into the vehicles, communicating through Nissan’s cloud infrastructure rather than requiring direct vehicle-to-vehicle connections.
The system addresses a common frustration with conventional adaptive cruise control, when maintaining safe following distances, other drivers frequently cut in, forcing the system to brake. Chou explains that Nissan’s engineers spent considerable time balancing this human behavior against system performance, continuously adjusting parameters to maintain optimal traffic flow.
When questioned about deployment thresholds, Chou revealed that simulation testing shows benefits increasing proportionally with adoption rates. Remarkably, noticeable improvements in traffic flow appear with as few as 4-5 percent of vehicles equipped with the technology. This relatively low penetration requirement makes the system practical for real-world implementation, though testing with limited vehicle numbers presents its own challenges for validation.
Future developments may include providing drivers with explanations when the system initiates slowing maneuvers, helping them understand the reasoning behind automated decisions rather than overriding the system. Should testing prove successful, Nissan envisions potentially licensing CCM technology to other automakers, creating an industry-wide solution for reducing traffic congestion through intelligent vehicle cooperation.
(Source: Ars Technica)