Bikers Can’t Whizz Around Driverless Cars: Says a Study

Self-driven cars are a potential cause of PTW collisions and highlight the disadvantages of ADAS

Naturally, self-driving vehicles have been in development for a long. Although Tesla is well-known, other, more reputable manufacturers are also moving in that approach. The United Nations (UN) declared earlier this year that the speed restriction for autonomous vehicles would be increased and that new testing would be implemented to ensure better motorbike rider recognition. Then, a few weeks ago, the UK government announced plans to allow self-driving cars on the nation's roads starting in 2020, with full implementation anticipated in 2025. However, there are still worries that autonomous vehicles won't be safe around powered two-wheelers since they lack adequate detection capabilities for Powered Two Wheelers (PTWs).

In a white paper, the Connected Motorcycle Consortium (CMC) examines the detecting capacities of autonomous cars with respect to PTWs. According to the European Association of Motorcycle Manufacturers (ACEM), "to prevent vehicle-PTW collisions and to reduce the incidence of motorcycle accidents, accurate identification of PTWs by passenger car ADAS is vitally required. Passenger automobiles must be able to recognize motorcycle maneuvers in regular traffic, such as weaving in and out of traffic, leaning while turning, and lane splitting. The Advanced Driving Assistance Systems (ADAS) can cause drivers of those vehicles to become more dependent on it and "less attentive to the driving task," according to research issued by the CMC. So, even as car-to-car incidents decline, the CMC predicts that car-to-PTW collisions could rise.

The CMC also discovered that small items, including PTWs, can be spotted but it takes time. According to the CMC, "it needs to be examined whether such latency is acceptable for a driver to react in time to avoid a collision if a PTW is recognized with lag in certain instances."

Additionally, there are issues with the "Radar Cross Section" (RCS). This is essentially the number of radar waves that a target returns to the radar source. For instance, a larger object will reflect more light than a smaller object. Signal to Noise Ratio also has an impact on detection (SNR). SNR can be compared to a filter that eliminates all of the minor radar detections (the CMC refers to this as "clutter") and concentrates on the key factors. The SNR can reject minor but important radar detections, such as PTWs if it is set too high. On the other hand, if it is set too low, the ADAS will consider the little, unimportant detections (also known as "clutter").

A vehicle's ability to be detected is compromised if its RCS is less than its Signal to Noise Ratio (SNR). Additionally, the detection of vehicles with lower RCs (i.e., PTWs) can be limited if there are nearby objects with a higher RCS. With camera-based ADAS systems, there is a similar detection issue where two tail lights that are placed close together can appear as a typical set of tail lights on a car farther away. According to Ryan from FortNine in the YouTube video below, this is one theory that might help to explain two recent incidents in which autonomous Teslas struck motorcycles from behind.

The CMC paper states that "Under certain circumstances, the detection of PTWs is challenging for Advanced Driving Assistance Systems (ADAS), due to the different way of motion, the slim shape, and as a result, the smaller radar reflectivity of PTWs compared to cars." The CMC believes that, at the moment, one of the most effective ways to improve PTW safety is to improve the conspicuity of PTWs by automotive systems.