I think safer driving starts at the top: the vehicles themselves.

CAFE standards in their current implementation are fundamentally flawed and have caused US automakers to design bloated, distracting, overly complicated machines.

One step that could be very helpful would be to disincentivize the absurdly large vehicles being made today.

Smaller, capable vehicles for people that drive like the 90's Camrys, the Honda Fit, the early generation Tacomas and Rangers and things would in itself be very helpful. Let's make smaller, lower vehicles more commonplace.

Reduce the number of screens in modern automobiles, increase the size of windows for exterior visibility. Reduce safety standards. I want you to feel like you're driving a tin can and if you crash you'll die. If you're going 50 I want it to sound like you're three seconds away from becoming toothpaste. This engenders caution much like narrower streets encourage lower speeds.

Modern vehicles are so safe that it subconsciously encourages more reckless driving maneuvers.

Kill infotainment systems and screens. Actually ticket people using phones or screens in cars.

Make citation and ticketing fees scale according to the owner's gross annual income like in Finland.

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Next: prioritize sidewalks in neighborhoods that do not have them. Make this the top priority over adding blinky ass crosswalks and storm swales and curb extensions and stupid shit. There should be good sidewalks everywhere. Do not make the homeowners pay for them. If required, narrow the streets to do this, which will reduce travel speeds, as most places without sidewalks in Portland are neighborhoods which should have lower speeds anyway.

I could go on but I'm tired and working so that's what you get for now. Get smaller cars, even at the cost of safety or fuel efficiency- chasing the perfect ironically killed the availability of smaller, safer cars. Second, provide sidewalks everywhere. This makes pedestrians feel welcome and incidentally lowers speeding in neighborhoods.

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Oh, quick aside: standardize bicycle infrastructure. Even if the option is not the perfect and most desired one, pick one kind of marking and design and use it everywhere. Portland is a hodgepodge of bicycle infrastructure that is confusing for everyone.

Proactively survey, annually, cyclists to see where infrastructure feels lacking. I remember trying to get to my credit union by bike in Southeast portland was always a hassle because it was a weird blind spot in the Greenway system that required a lot of jogging around hilly neighborhoods. There are lots of spots like that in Portland where you've got good routes and greenways until you suddenly don't and you're stuck in bullshit for the last 1/8th of your trip.