Does that really make much of a difference? The comparison is to trends, not to raw numbers. Some locales saw fatalities up, others dropped. Unless there were significant variances between the listed locales in population movements into or out of those locales during those years, the trends would provide a ballpark yardstick for comparison.
Also linked to in that article was the experience of the state of Kansas after a 5 mph bump-up in speed limit.
http://www.kansas.com/news/state/article4970385.html
Three years after the state raised the speed limit 5 mph to 75 on certain highways, fatalities and injuries are rocketing, according to new numbers compiled by the state Transportation Department.
The overall number of crashes is flat, but highway deaths jumped 54 percent since 2012 on the seven highways where the speed limit was raised.
Those highways, covering 804 miles, include I-135 north out of Wichita, rural stretches of I-35, I-70, U.S. 69 and I-470 near Topeka.
Overall, 48 people were killed in 38 wrecks on those seven highways in the two years before the speed limit was raised in mid-2011. In the two years after the speed limit was raised, 74 people were killed in 59 wrecks.
Injury accidents are up, too, increasing by 13 percent in the past two years compared with the two years before the speed limit went to 75.
Heavily traveled I-35 was one of the highways with the biggest increases in fatalities. Fatal wrecks doubled to 18 on I-35 in the two years after the speed limit increased compared with the two years before it was raised.
State highway officials aren’t ready to pin the blame for rising highway deaths on the higher speed limit, but national traffic safety experts think it follows a pattern seen in studies elsewhere.
Read more here: http://www.kansas.com/news/state/article4970385.html#storylink=cpy
That's a pretty big shift and it might just be a coincidental spike. If a few years down the road it turns out that it is not a spike but instead a trend, how would you begin to explain a 54% hike in fatalities over just three years? Are people driving 54% further now? Are there 54% more drivers and cars on the road now? Have 54% more drivers suddenly discovered texting and driving or resumed drinking and driving?
Or has that slight up-tick in travelled speed worked to overcome the ability of vehicle safety and survivability features to protect vehicle occupants in crashes which by the laws of physics become exponentially more brutal and violent as speed ticks up?
