Vision Zero Safety Study | Page 27

Unsafe speed was a factor in 35 percent of all fatal collisions Citywide .
As driver speed increases , the field MPH of vision narrows .

Why

Unsafe speed was a factor in 35 percent of all fatal collisions Citywide .

HIT BY A VEHICLE TRAVELING AT :

20

As driver speed increases , the field MPH of vision narrows .

10 %

DEATH RISK
SPEEDING
High Speeds Increase the Likelihood of Collisions Vehicle speed affects a driver ’ s peripheral vision . As speed increases , the visual field narrows , limiting the ability of the driver to see other activity on the periphery , such as a person riding a bicycle on the side of the street or a person entering the crosswalk . 5
In addition to limiting the field of vision , higher speeds also increase the distance required for a driver to stop in time to avoid a collision . In general , doubling the speed of a car increases the total braking distance nearly four times . 6 This combination of limited vision and longer braking distance explains why unsafe speed is the most common violation category among all collisions in Los Angeles .
HIT FIELD BY A VEHICLE
OF TRAVELING VISION AT AT : :

20 30

MPH

40 10 %

DEATH RISK
HIT BY FIELD A VEHICLE OF
TRAVELING VISION AT AT : :

40 30

MPH

40 80 % DEATH RISK

5 Astrid Bartmann , William Spijkers , and Manfred Hess , “ Street Environment , Driving Speed , and Field of Vision ,” in Vision in Vehicles III ( Evanston , Illinois : Northwestern University , 1991 ), 381 – 389 .
6 Road Safety Authority , “ Stopping distances for cars ,” in Rules of the Road ( Dublin , Ireland : The O ’ Brien Press Ltd , March 2015 , 115 – 19 , accessed November 3 , 2016 , http :// www . rotr . ie / Rules _ of _ the _ road . pdf .
VISION ZERO SAFETY STUDY 27