You were going to fast for the existing conditions. When on the highway I need to be able to stop and so my speed depends on the traffic and my sight distance, and the condition of the road, whether it is covered with sand or water, whether it is smooth or bumpy as hell as that affects my ability to brake and stop the bike.
When I sold a four wheel drive station wagon and bought a sports coupe it took awhile to adjust to having so many motorists turn in front of me when I had the right of way. Even drivers in Volkswagen beatles would turn in front of my small car. When sailing on SF bay I quickly learned that many sailors believed the large sailboat had the right of way.
The worst part is that the motorist is usually the one that gets to talk to the police officer and so the reports nearly always show that the bicyclist was at fault.