> the driver has enough expertise to know what his personal limit ought to be

It is actually somewhat amusing that you worded this as "ought to be" rather than "is". Because one of the big problems with most drivers is they have an overly inflated idea of how competent they are at driving (I am not so churlish as to exclude myself from the category). And our system does nothing to bring drivers' beliefs about their capabilities in line with their actual capabilities--drivers are tested generally once on their competence [1], and that pass result then gets to hold for several decades, physical or mental decline notwithstanding.

> I settle for a middle position, which is that the speed limit should be no less than 35 mph on most streets

Most residential streets are not safe to travel at 25 mph, let alone 35 mph. There's a line of parked cars in the shoulders, children playing in the driveways, sidewalks, and street? Yeah, if you're traveling 35 mph, you've got no hope of stopping in time (recall that stopping distance goes to the square of speed).

> Moreover, I think that all pedestrian collisions, no matter how small, must be investigated thoroughly, with a hard action taken to minimize such an incident.

We already know how to minimize collisions. The top 3 actions to take are a) reduce speed limits, b) redesign roads to be narrower to make drivers less comfortable traveling at speed, and c) ban right turns on red.

> Bicyclists must be mandated to wear light-colored high-visibility clothing, reflective gear, and a helmet, otherwise their bicycle should be confiscated.

Why? It's not like wildlife like bears, moose, or deer that wander onto the roads wear such gear, and a "mature highly-attentive driver" should be equally aware of such dangers.

[1] And to be honest, even that is somewhat generous a statement.