A nationwide speed limit < or = 65 miles per hour will save thousands of lives.
BACKGROUND
The objective of this study was to measure the impact of higher speed limits on traffic deaths several years after the repeal of the 55 miles per hour (mph) National Maximum Speed Limit (NMSL).


METHODS
Traffic fatality rates for 2003 were calculated for all 50 states and the District of Columbia, and compared between states with speed limits < or = 65 mph versus greater than 65 mph, adjusted for state differences in vehicle miles traveled and other potential confounding factors using negative binomial regression.


RESULTS
In 29 states with speed limits greater than 65 mph, there was a 13% increase in the risk of traffic fatalities (risk ratio 1.13, 95% confidence interval [CI] 1.03 to 1.24, P = .009). An estimated 2,985 lives may be saved per year with a nationwide speed limit of 65 mph or less.


CONCLUSIONS
Nationwide restriction of speed limits to 65 mph or less will save almost 3,000 lives every year.
Shafi
Shahid
S
Division of Burns, Trauma and Surgical Critical Care, Department of Surgery, University of Texas Southwestern Medical School, 5323 Harry Hines Blvd., Mail Stop 9158, Dallas, TX 75390-9158, USA. shahid.shafi@utsouthwestern.edu
Gentilello
Larry
L
D000063:Accidents, Traffic / Q000331:legislation & jurisprudence / Q000517:prevention & control / Q000706:statistics & numerical data; D000328:Adult; D001334:Automobile Driving / Q000331:legislation & jurisprudence / Q000592:standards*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012189:Retrospective Studies; D012424:Rural Population; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology; D014505:Urban Population; D014947:Wounds and Injuries / Q000453:epidemiology / Q000209:etiology / Q000517:prevention & control