What an awful series of events, and it's shattered that family and beyond. My condolences to all affected by it.
As someone who lived in central New Jersey and is familiar with how drivers on winding roads act in the hillier parts of the state, I quickly developed an innate distrust of everyone driving on the roads there. Biking at dusk sounds benign in a city, even the responsible thing to do from a climate point of view. In rural New Jersey... man, I don't think there's any way I'd do it around vehicles at dusk. I'm not sure there's much more dangerous than a winding and hilly rural road, in a forested area, with a 45mph speed limit. Give me a well-lit, eight-lane highway straightaway any day.
That's no place for a cyclist unless it's on designated bike paths (and not just "bike lanes" painted onto the shoulder of the road). The drivers are too reckless. In this kind of matchup, it doesn't matter if you have the right of it. You're losing any collision you're involved in with a vehicle larger than you are... it's the same reason why if it's late at night and you're pulling up to a light in a deserted rural area, and you see a semi coming perpendicular to you, you take 5-10 extra seconds, yield, and just let him go. It doesn't matter if you have the light. You can be right and still end up a skidmark if the other vehicle dwarfs yours. Bikes and motorcycles take one bump and it's all over.
Area residents know there are so many nasty car accidents and worse in highly populated central NJ, from inexperienced student drivers to drunk drivers to, hell, just the sheer volume of accidents involving cars and deer.
It's an awful story. You hear far too many like it. Whether it's for deterrence or just to get them off the road, I'd harden punishments for this kind of crime. Far too many people consider drunk driving to be no big deal but it's devastating far too frequently.