Fremont seems to be using north-south block numbering that originates at 1st Avenue in Oakland, as do other communities between them, such as San Leandro and Hayward. Although in some places this numbering is superceded by numbering centered on the individual community - asumably a result of the town centers already having their own numbers before the common center of Oakland was extended outward. You can follow this on a map using the numbered streets closer to Oakland - the numbered streets extend as far as 174th Ave. which is in Castro Valley. Houses just south of that cross street are numbered in the 17400 block. Being farther away, Fremont blocks are in the 30,000s and 40,000s. If the numbered streets extended all the way to Fremont, 47400 Kato would be at the corner of Kato Rd. and 474th Avenue.
Thus, the higher the number, the safer the neighborhood, once you get sufficiently high.
In general, I like sensible systems. The above is a sensible system (keeping one numbering axis per axis). Another sensible system is the idea in LA area that streets go forever and don't change names, regardless of county, city, etc.; unfortunately, San Jose takes the opposite approach, naming every block of every road a different name; it's horrendous! Another sensible system is reducing the number of appendages and prefixes for roads; getting rid of "Ave", "St", "NW", "NE", "N", "S", etc; if any of those are used, then I prefer those systems that at least make a sensible use of them (such as NYC which has St and Ave mean which axis it is on (Ave is Y and St is X)). Another sensible system is to use first letters correspond to numbers in the address, and yet another sensible system is to use a category, such as tree names, animal names, Nobel winners, or whatever. Another sensible system is to use the shortest possible names. The best system would combine all or most of those attributes. But, alas, everything is a hodge podge; LA uses multiple numbering systems, San Jose uses multiple road names, and Portland uses all sorts of appendages that are awful.
I applaud Fremont for being sensible in this manner.
My only complaint is that its center point is a hell hole.