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Higher Speed Limits Have Killed at Least 33,000 People in the U.S. over the Last 20 Years, IIHS Reports


Speed limits across the nation have been on the rise over the past two decades since Congress repealed the National Maximum Speed Limit (NMSL) law in 1995. Some have argued that these speed limit increases are simply aligning the law with reality, given that many motorists are regularly driving at speeds that exceed 55 miles per hour (mph) – the limit set by the NMSL.

A new study, however, has revealed that these speed limit increases are coming with a big cost – namely, the cost of thousands of lives.

In fact, as the Insurance Institute for Highway Safety (IIHS) has reported, the speed limit hikes that have occurred across the U.S. over the past two decades have contributed to at least 33,000 traffic-related deaths. This high fatality rate has “been so great that it has now largely offset the beneficial effects of some other traffic safety strategies1,” IIHS has pointed out.

Details & Findings of the IIHS Speed Limit Study

To evaluate the impacts of speed limit increases across the nation, IIHS researchers analyzed traffic fatality data versus speed limit increases for 41 states (leaving out 9 states and the District of Columbia due to their low rates of vehicle miles traveled).

In examining this data, researchers focused on fatality rates per billion miles driven (per state), taking note of what type of roads these deaths were occurring on (i.e., rural versus urban interstates). They also reportedly accounted for other factors that may contribute to roadway fatalities, like drunk driving.

What they discovered from their analyses was that:

  • When speed limits go up, drivers will go even faster than the new speed limit, increasing the risk of auto accidents.
  • For every 5 mph that speed limits increased, there was generally a 4-percent increase in the death rate (for a given roadway).
  • Freeways and interstates, which were associated with the highest increases in speed limits, saw a roughly 8-percent spike in fatal crashes over study period.
  • In 2013 alone (the last year of the 20-year study period), speed limit increases contributed to at least 1,900 deaths.
  • These fatality estimates are likely conservative, as a number of states have continued to elevate their speed limits since 2013 (with at least five states in the U.S. now having speed limits set as high as 80 mph).

Commenting on this study and its findings, lead study author and IIHS vice president of research and statistics, Charles Farmer, has explained that:

Since 2013, speeds have only become more extreme, and the trend shows no sign of abating… We hope state lawmakers will keep in mind the deadly consequences of higher speeds when they consider raising limits.

What do you think of this study and its findings? Has this inspired you to be more careful about complying with posted speed limits? Tell us what you think on Facebook & Google+.

Contact a Columbia Personal Injury Lawyer at Chappell Smith & Arden, P.A. Attorneys at Law

If you have been injured in an auto crash – or if you have lost a loved one to a fatal traffic wreck, contact a Columbia SC personal injury lawyer at Chappell Smith & Arden, P.A. for clear answers about your rights and recovery options.

At Chappell Smith & Arden, P.A., we know that no amount of money can ever erase the impacts of serious or fatal traffic accidents. We are also aware, however, that financial recoveries can be pivotal to helping injured people and/or families during these challenging times, as compensation can provide them with the resources necessary to cover medical bills, funeral costs, etc. That, in turn, can be the key to helping survivors reclaim their lives.

Call our firm at 866-881-8623 or contact us online to set up a free, no obligations initial consult with one of our lawyers. During this meeting, you can find out more about your rights, as well as how we can help you.

From our six office locations throughout South Carolina, our attorneys provide the highest quality legal services to injured people and families in Columbia, Alken, Camden, Sumter, Orangeburg, Greenville, Florence, Beaufort, Irmo, Spartanburg, Myrtle Beach, Hilton Head Island, West Columbia, Rock Hill, Charleston, Lexington, Winnsboro, Summerville, and throughout South Carolina.


1: Examples of ‘traffic safety strategies’ include (and are not limited to) speed cameras, heightened enforcement by police, and even vehicle safety technologies (like airbags).

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