“San Jose fixed on Highway 17 bus” by Richard Masoner is licensed under CC BY 2.0

The latest annual report on motor vehicle collisions from the California Highway Patrol has a ton of information about what’s happening on California roads and highways, with extensive datasets on alcohol- and truck-involved collisions and more tightly focused summaries of collisions involving pedestrians, motorcycles, and bicycles.

The special attention given to truck drivers piqued our curiosity. CHP uses two tables to highlight collisions involving pedestrians and bicyclists, one looking at collisions month by month and another that separates victims by age. CHP uses five tables for collisions involving motorcycles. By contrast, it uses 12 tables to highlight collisions involving trucks, looking at collisions month by month and county by county as well as by the age of the drivers, primary collision factors, and what kind of movement a truck was making just before a collision occurred.

Shouldn’t CHP be reporting on collisions involving pedestrians, motorcycles, and bicycles to the same extent as truck collisions?

This question prompted us to use today’s post to examine the relative impact of collisions involving trucks, alcohol, pedestrians, motorcycles, and bicycles on traffic safety in our San Jose community. As always, the intent is not to point fingers but to raise awareness about safety risks and influence public programs seeking to improve traffic safety.

As we learned by examining CHP data, trucks accounted for the smallest share of collisions statewide as well as the San Jose area within the boundaries of Santa Clara County. Bicycles were at the high end of the range. Here’s a simple, categorized snapshot of how many injury collisions we see in a year in Santa Clara County:

Bicycles 700+
Alcohol 600+
Pedestrians 400+
Motorcycles 300+
Trucks <100

Source: California SWITRS report

This post looks at each of these five collision categories to find out how Santa Clara County has managed to limit injuries and fatalities compared to the statewide average.


Auto collisions with bicyclists is a bigger problem in the San Jose area than collisions involving alcohol. Let that sink in for a minute.

You can’t chalk up the problem to San Jose’s population size, either. Santa Clara County has the sixth-largest population in California, but it has the fourth-highest number of bicycle-involved collisions. More bicycles are involved in injury collisions and fatal collisions in Santa Clara County than the statewide average.


Alcohol is involved in more than one-third of traffic fatalities throughout California. In Santa Clara County, alcohol has played an even bigger part in the unnecessary loss of life, affecting 42 percent of traffic fatalities.

By the same token, Santa Clara County has fewer alcohol-involved injury collisions than you’d expect based on statewide figures. About 10 percent of California’s injury collisions involve alcohol, while in the San Jose area it’s slightly over 9 percent.


Here’s another mind-boggling fact about traffic safety in Santa Clara County. Pedestrians were involved in almost as many fatalities as alcohol. We’re talking about 35 pedestrian-involved fatal collisions in 2013, compared with 39 alcohol-involved collisions.

All in all, pedestrians are far more likely to be involved in a fatal collision in Santa Clara County than the California average. Pedestrians show up in almost 38 percent of Santa Clara County collisions, compared to 26 percent statewide.


If you tend to believe that bicycles are generally safer than motorcycles, here’s one remarkable example that suggests otherwise. In Santa Clara County, injury collisions affected two bicyclists for every one motorcyclist on the road. Bicyclists were also involved in more fatal collisions than motorcyclists.

The scenario is much different at the state level, where the number of injury collisions involving bicycles is comparable with motorcycles, and motorcycles were involved in far more fatal collisions than bicycles.


Santa Clara County has fewer truck-involved traffic collisions than other counties a fraction its size. That’s true whether you’re looking at injury collisions or fatal collisions. Trucks were involved in 1.5 percent of injury collisions in the county and about 4.5 percent of fatal collisions. In each case, that’s about half as many trucks as you’d expect to see, based on statewide figures.


Santa Clara County and California Motor Vehicle Injuries & Fatalities, 2013







County injuries

721 609 460 366 96

% of total injuries

11% 9.3% 7% 5.6% 1.5%

State injuries

13,213 16,060 11,623 11,644 5,209

% of total injuries

8.4% 10.2% 7.4% 7.4% 3.3%

County fatalities

8 39 35 7 4

% of total fatalities

8.6% 41.9% 37.6% 7.5% 4.3%

State fatalities

165 1,075 749 467 256

% of total fatalities

5.8% 37.7% 26.3% 16.4% 9%

Source: California SWITRS report