Examining Crashes in San Jose; Who's at Fault, and What Can be Done to Fix it?

I decided to explore road safety in my home town of San Jose, CA, and I found some relevant GIS data showing a map of fatal or major injuries from 2013-2017, shown below.

What stands out to me at first is where the most incidents occurred, they're mostly at the intersections of major streets. This means that one or both of the involved streets has a speed limit of 35 mph or higher. That got me thinking, what type of intersections are these crashes occurring at? Signals? Stop signs?

From the map above it can be unclear, but it seems to be mostly stop signs. What about the victims in these crashes?

So far there isn't one group that is standing out, what if we overlay the map above with the amount of crashes? The summarize tool tells us that 504 victims were in motorists, 300 were pedestrians, and 136 were bicyclists. 

From the above map, we can see that the sites where multiple crashes have taken place, a motorist tends to be the victim more times than not. Let's examine that big red dot just east of Downtown, and see what information we can conjure up. We can tell that a motorist is the victim, but what about the intersection type?

Above is the intersection of Santa Clara and 22nd St. What we can tell now is that there were 7 people across 2 incidents in a motor vehicle that were seriously injured at an intersection with a one-way stop sign. Now it's unknown which street the victims and perpetrator(s) were on, but from the attribute table it is known that the 3-person incident occurred at 5:12 PM in the springtime, and the 4-person incident at 10:53 PM. That suggests that the second incident could have had foul play involved, possible drunk driving. Since the first incident occurred in broad daylight, foul play is less realistic (although still possible). Just down the street an incident with 3 major injuries occurred at a signalized intersection, but it was at 1:37 AM, easy to suspect foul play. 

All told, people in motor vehicles seem to be the victim more times than not, especially at the intersections where more people were seriously hurt. However that data is flawed because if there are more people in the vehicle, then those red circles will be bigger, as the data does not show frequency of crashes. It's easy to say that cars are the problem, which they certainly can be with foul play likely involved late at night, and since there were more motorist victims than pedestrian and bicyclists combined. However, more research needs to be done to determine frequency of major/fatal crashes, which will show a better picture to determine if intersections play a factor or not.