The recent trial staged by Nokia and Japanese Telco KDDI claiming to be the first application of LTE broadcast to vehicle-to-vehicle (V2V) communications represents another small step towards widespread autonomous driving. The test was carried out to test whether broadcasts to all cars within proximity would work as intended for V2V applications. But it also illuminates how much remains to be done to build the required underlying infrastructure. There is a big difference between putting a few self-driving cars on the road and making the system work safely on a large scale where autonomous vehicles must coexist with each other but still cope with many legacy vehicles on the road. This will require full V2X communications where vehicles communicate in…