“going 17mph over the limit... that is a clear cut case of meriting a ticket when a cop sees that.”
Not always the case. In my neighbor there is one spot that quickly goes from 55 MPH to 45 zone to 35 zone. A cop sits right at the beginning of the 35 zone and can ticket pretty much anybody he wants.
We have tons of those where I drive. Many of these signs tend to be oversized and might even have those red flag thingies on them so that they stand out. I don't think the "I wasn't paying attention to the signs" excuse is going to get someone very far with the cops, especially in a residential area with a lot of cars.