Speed is especially lethal for vulnerable users like people walking and biking .
High Speeds Dramatically Increase the Severity of Collisions Research consistently shows the destructive potential of vehicles traveling at high speeds . Our Los Angeles data confirm these findings : Unsafe speed contributed to 35 percent of all fatal collisions Citywide .
Speed is especially lethal for vulnerable users like people walking and biking .
The effect of vehicle speed on the likelihood of survival depends on the transportation mode of the other party involved in the collision . For vehicle-to-vehicle collisions , numerous technological advances in vehicle design have improved the likelihood of survival . Unfortunately , people walking or bicycling do not have many of the same protective features , making them more vulnerable when hit by vehicles traveling at speeds greater than 20 miles per hour . A U . S . Department of Transportation review of studies to date found that increasing vehicle speed from 20 miles per hour to 40 miles per hour increases the likelihood of a pedestrian death when hit from 10 percent to 80 percent . 7
This explains why arterial streets , which combine a high number of vulnerable people with cars moving at relatively high speeds , are so deadly and make up a high proportion of the HIN .
IF HIT BY A PERSON DRIVING
20 MPH
CHANCES OF SURVIVAL
80 %
40MPH
10 %
7 W . A . Leaf and D . F . Preusser , Literature Review on Vehicle Travel Speeds and Pedestrian Injuries ( Washington , D . C .: U . S . Department of Transportation , National Highway Traffic Safety Administration , October 1999 ).
28 CITY OF LOS ANGELES