Pandemic paradox: Crashes deadlier on clearer roads

The number of North Carolina residents who have tested positive for coronavirus has grown in recent days, reflecting a trend seen in a number of other parts of the nation. Health officials have expressed concern, but as of this writing, few expect a return of the stay-at-home order issued by Gov. Roy Cooper in late March and then eased in early May.

April traffic was down across the nation

Fayetteville traffic dropped significantly during the period, leaving city streets, freeways and interstates noticeably clearer. Much the same happened across the U.S. throughout the month of April.

Despite its many tragedies and profoundly negative impact on the nation, the pandemic presented an opportunity for researchers to examine the effects of a lockdown on various aspects of American life. For instance, the Center for Transportation Safety at the Texas A&M Transportation Institute studied how a dramatic reduction in traffic affects road safety.

Shattering assumptions

A person might reasonably assume that driving would be notably safer in the absence of normally heavy traffic, the study’s results might not fit reasonable assumptions. While researchers found that the number of motor vehicle crashes in April dropped by nearly 50 percent compared to 2017-2019, the number of fatalities dropped by only 20 percent.

They found that while there were about half as many crashes, “there were about 50 percent more crashes resulting in a fatality during this time period compared to previous years,” a news report about the study stated.

The pandemic’s paradox

TTI Senior Research Engineer Robert Wunderlich said the risk of death or serious injury in a particular crash is actually greater when roads are clearer.

His research team studied traffic in both rural and urban settings, as well as wrecks involving a single vehicle and wrecks with more than one. The put assigned the crashes into six categories:

• All single-vehicle
• All multi-vehicle
• Urban single-vehicle
• Rural single-vehicle
• Urban multi-vehicle
• Rural multi-vehicle

A look at the numbers

The number of both single- and multi-vehicle crashes were down by 23 percent and 55 percent, respectively, the proportion of wrecks with at least one death rose by 14 percent for single-vehicle wrecks and 59 percent for multi-vehicle wrecks.

The research team found that the proportion of urban multi-vehicle wrecks resulting in at least one death nearly doubled.

Faster, yet still legal

Wunderlich said that speed primarily determines crash severity, but that excess speed wasn’t necessarily the problem during the pandemic. His team found that peak average speeds on Houston’s freeways rose from less than 45 mph to 65 mph. “So all crashes occurred at higher, yet legal, speeds.”

The reduced traffic levels enabled drivers to go faster than they would normally be able to, but that drivers weren’t going above the speed limits. The higher average speed meant that collisions were at greater speeds than normal – which made the crashes more likely to be deadly.