A recent ornithological study into the deaths of 200 crows found by the side of an outback highway in South Australia found that 98% had been killed by a sudden impact with a truck and 2% by an impact with a car. The study went on to report that crows always work in pairs. While one eats the road kill, the other acts as a lookout in a nearby tree or power pole to warn it's mate of an on coming vehicle.

It was found that the lookout crow had the ability to crow, "carr, carr, carrrr...!! but NOT the ability to crow, "truck, truck, truckkkk...!
Hence the reason for the disproportionate number of deaths by truck.....lol