There is no doubt that the Covid-19 pandemic has rearranged much of American life. Because much of the U.S. was in lockdown this past April, traffic levels dropped dramatically not only in Belleville, St. Clair County and the St. Louis metro area but across the nation and around the world.
Though streets, roads and highways were all clearer, they were not substantially safer, according to a new study.
Contrary to expectations
The results of the study conducted by the Texas A&M Transportation Institute (TTI) were contrary to what was widely expected, finding that though motor vehicle crashes in Texas dropped by nearly half, the proportion of those accidents that were fatal rose by 50 percent. In other words, though roads were clearer and there were dramatically fewer auto accidents, there was only a 20 percent drop in traffic fatalities.
According to an article from Traffic Technology Today, that meant that any crash during the month of April “was more likely to be fatal than it would have been when traffic levels were normal.”
Urban and rural
Because Belleville is close to both urban and rural settings, readers here might have a better appreciation of the fact that TTI researchers studied traffic data from both urban and rural settings, analyzing the numbers in several categories:
- All single-vehicle crashes
- All multi-vehicle accidents
- Urban single-vehicle crashes
- Urban multi-vehicle crashes
- Rural single-vehicle wrecks
- Rural multi-vehicle accidents
A look at the study’s findings
TTI researchers found that both multi- and single-vehicle crashes were down 55 percent and 23 percent respectively. However, the proportion of auto accidents in April with at least one fatality rose 14 percent for single-vehicle wrecks and 59 percent for multi-vehicle wrecks.
“With fewer vehicles on the road in April, it makes sense that we had fewer multi-vehicle crashes,” said TTI senior research engineer Robert Wunderlich. “And there is evidence that the relationship is exponential, meaning that decreases in volume can have a greater than proportional effect on crashes. The reduction in single-vehicle crashes is more likely to be proportional to the decrease in traffic.”
Exposure and risk
Wunderlich said exposure and risk are the factors affecting motor vehicle crashes. Exposure is simply the amount of travel and risk is the chance that travel results in an accident, injury or death.
Exposure was down in April because there were fewer drivers and vehicles on the nation’s roads, which meant there were fewer crashes. But fatal accidents dropped by only 20 percent during that month, so the risk of a fatal accident was greater than normal.
Increase in average speed blamed
Wunderlich said that speed is the main factor that determines crash severity. He said a 10 percent reduction in speed results in 38 percent fewer fatalities and 27 percent fewer serious injuries.
Unsurprisingly, perhaps, clearer roads did not result in April’s drivers slowing down. The researcher said that peak-period average speeds on Houston’s freeways rose dramatically: going from 45 mph before the pandemic to 65 mph in April.
“So all crashes occurred at higher, yet legal, speeds,” Wunderlich said.
He said that while excessive speed played a role in the April fatality rates, it was not as big of an issue as the increase in average speed.
A final word
Wunderlich’s final take on exposure and risk: “Basically, we reduce our risk when we slow down, pay attention and stay sober. Until we get self-driving cars, the best way to reduce risk is the old-fashioned way: by making safer choices.”
We couldn’t have said it any better.