MAGA, I've commuted in the US from the 70s until 2018 when I retired for the third time. This has been done in CO, SD and WY. I have had 3 accidents I would consider serious..a broken pelvis due to carelessness, 2 cracked ribs from being hit by a car turning into the dawn sun, and a concussion caused by having a tire caught by the pavement after going on the dirt to avoid pedestrians and returning to the bike path.
These experiences have caused me to create some rules for myself.
Be visible. Lights in the dark and hi vis all the time.ppl
Obey the law as if driving a car. Signal turns, don't run lights or stop signs, and do not assume drivers will do these things.
Look out for the unexpected. Car doors, dogs , children, black ice, people on the phone or walking and talking in herds obliviously are some examples.
Discover the safest routes and learn what parts are the least safe. Learn these routes when you don't have to be somewhere.
I began riding fixed gear and later, folding bicycles, because I tend to zone out when riding, especially on a route I've ridden many times. I had to pay attention on these bikes, at least at first. Paying attention is critical and goes along with heightened situational awareness, and looking out for possible problems. To paraphrase Pogo, I have met the enemy and he is me. I don't know how many times I've had my head down, pedaling against a head wind, to look up and see a parked car in front of me, another biker or a dog when a minute ago there was nothing.
Know your bike, make sure it's working properly and develop muscle memory so as you sense a threat your hands are already on the brakes instead of fumbling for them. Learn to ride with others so no one gets hurt. More fun, too.
This stuff may seem obvious but I see people riding with ear buds, running lights, going to fast for road conditions all the time.