As somewhat hinted in Steve's post, there are a lot of different areas of the city, from areas with extreme density of intersections, to areas more desolate than suburbia, to expressways. Most of the enforcement (of everything) is going to happen in the dense areas where the people are.

Those are also the areas where fully complying with the law while cycling is the most frustrating. They're also the areas where the opportunity to commit a moving violation with a motor vehicle is reduced - you can't really speed or go through a red light if there's another vehicle in front of you.

That's indeed a very serious and officially neglected safety issue overdue to be taken seriously (the cops habitually do it themselves), but parking violations are not moving violations. Regardless who is writing the ticket, it's going to go under a different total. Fun fact: the city actually has a deal with fleet companies where in return for not contesting parking tickets, they only have to pay a fraction of them.

People tend to forget that truck routes are through truck routes. Except where there are clearance or load issues, trucks can legally use other streets to get to their local destination. That doesn't mean things aren't done illegally, but it does mean that to enforce an off-route truck you have to recognize a pattern or be investigating subsequent to something else which exposes the actual purposes of the trip.

What is widely neglected and easy to spot are full length 18-wheelers, which are illegal in the city. But most of the carnage seems to be box trucks and especially private garbage trucks.

The garbage trucks are really the only motor vehicles you'll regularly see committing violations of the traffic laws as they are written in dense parts of the city at the same habitual rate as cyclists - and probably for similar reasons of trying to do something that doesn't really fit the usual traffic flow.

Not sure exactly what you mean, but again you generally have to be first in line to commit a violation with a motor vechicle, since shoaling doesn't really work with large boxes. The reality is that motor vehicles honor red lights the overwhelming majority of the time, while daily observation would suggest that cyclists violate them a simple majority of the time. And as much as motor vehicles like deeply orange "yellows", there will often be a bike coming through still later.

Only in specific times and places is there the physical opportunity to speed. Since trucks aren't allowed on most of the parkways, those would generally be the main stretches through more auto-centric or still industrial parts of the city. And indeed some of those are problematic. Progress is being made in school zones with camera enforcement, but those tickets fall in a different statistical (and legal) category than manually written ones.