Studies and data

The first step in preventing collisions is knowing how and why they happen. With this information, we can take steps to avoid them.  Education and enforcement efforts should focus on the most common causes of collisions and fatalities.  CROW has conducted research into Corvallis bike/ped collisions, and compared local results to twenty years of similar studies.  The general overview is below:

A comprehensive Portland study looks into causes of car collisions and fatalities.car collisions - factors

car collisions - FATALITIES

.

Corvallis’s data for car/bike collisions is shown below.  bike - all causes - for online graphics

.

For fatalities, there are too few in Corvallis (fortunately) to determine statistics.  Throughout the nation, there are very few studies of fatalities.  This New York City study is the most recent and comprehensive study on fatalities, and smaller studies conducted afterwards show general agreement.causes of car vs bike fatalities

.

Corvallis’s data on car/pedestrian collisions is shown below.ped - all causes - online graphic

.

CONCLUSIONS

In fatal car collisions, alcohol and drugs are the largest contributor.  However, speed and aggressive driving, which are far more accepted in society, each contribute to nearly half of all fatal collisions.  Education and enforcement of these issues will drastically save lives.

For bicycles collisions, motorists turning into the path of bicyclists is by far the most common cause of collision, and the #2 cause of fatality.  The #1 fatality is from unsafe motorist passing of cyclists.  Therefore, education and enforcement of these issues will make the biggest safety difference.

The stereotype of cyclists being reckless is not supported by data.  The top 4 causes of bike/car collision and fatality are motorist-caused.

For pedestrians, the data is completely one-sided.  Notice how the #1 and #2 issues swamp all other issues.  Teaching drivers to look both ways before travelling through a crosswalk or sidewalk, will prevent the most collisions.

For more details on this data and links to numerous similar studies, here is CROW’s full report on the behavioral causes of collisions in Corvallis.