Raised speed limits, speed spillover, case-fatality rates, and road deaths in Israel: a 5-year follow-up.
OBJECTIVE
We assessed the 5-year, nationwide impact on road deaths of the raise in the speed limit (November 1, 1993) on 3 major interurban highways in Israel from 90 to 100 kph.


METHODS
We compared before-after trends in deaths as well as case fatality-an outcome independent of exposure (defined as vehicle-kilometers traveled).


RESULTS
After the raise, speeds rose by 4.5%-9.1%. Over 5 years, there was a sustained increase in deaths (15%) and case fatality rates (38%) on all interurban roads. Corresponding increases in deaths (13%) and case fatality (24%) on urban roads indicated "speed spillover."


CONCLUSIONS
Immediate increases in case fatality predicted and tracked the sustained increase in deaths from increased speeds of impact. Newtonian fourth power models predicted the effects of "small" increases in speed on large rises in case fatality rates. Countermeasures and congestion reduced the impact on deaths and case-fatality rates by more than half.
Richter
Elihu D
ED
Hebrew University-Hadassah School of Community Medicine and Public Health, Unit of Occupational and Environmental Medicine and Injury Prevention Center, Jerusalem, Israel. elir@cc.huji.ac.il
Barach
Paul
P
Friedman
Lee
L
Krikler
Samuel
S
Israeli
Abraham
A
D000063:Accidents, Traffic / Q000331:legislation & jurisprudence / Q000401:mortality* / Q000517:prevention & control / Q000706:statistics & numerical data / Q000639:trends; D001334:Automobile Driving / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data; D015984:Causality; D015986:Confounding Factors, Epidemiologic; D003441:Crowding; D006801:Humans; D007557:Israel / Q000453:epidemiology; D008029:Lighting / Q000331:legislation & jurisprudence; D011159:Population Surveillance; D011237:Predictive Value of Tests; D012044:Regression Analysis; D018570:Risk Assessment; D017751:Safety Management / Q000331:legislation & jurisprudence / Q000379:methods / Q000639:trends; D012622:Seat Belts / Q000331:legislation & jurisprudence; D014504:Urban Health / Q000706:statistics & numerical data / Q000639:trends; D014947:Wounds and Injuries / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control