Which of the following is NOT a common cause of car-bicycle crashes?

Motorists texting while driving is identified as the correct answer because while it is indeed a dangerous behavior that increases the risk of all types of crashes, it is not typically recognized as a common cause of specific car-bicycle crashes in the same direct manner as the others listed. Texting takes a driver's attention away from the task of driving, which can lead to broader distractions and not immediate interactions with bicycles as seen in the other scenarios.

The other situations, such as motorists pulling away from a stop sign, making unprotected left turns, and turning right across the path of bicycle traffic, are direct interactions that often lead to collisions with bicycles. These actions involve moments of merging or crossing paths where the risk for accidents is significantly heightened, thus making them more prevalent causes of car-bicycle incidents. Understanding these specific interactions helps in recognizing patterns of behavior that can be modified to enhance safety for both cyclists and drivers on the road.