The Bigger They Are, The Slower They Stop: The Importance of Following and Braking Distance

Michael GrossmanMarch 06, 2018 5 minutes

It no secret that as more people more to Texas, our roads become increasingly crowded. One of the first casualties of crowded roadways is proper following distance between vehicles. An incident in Southeast Texas made me ponder this dangerous element of modern driving culture.

Copperas Cove, TX: January 17, 2018

65-year-old Roseann Lucidi of Kempner was fatally injured in a four-vehicle wreck near Copperas Cove on Wednesday, January 17.

According to local authorities, the crash happened around 4:50 p.m. on the U.S. Highway 190 bypass, just south of town.

Investigators with the Texas Department of Public Safety stated that a flatbed Freightliner semi-truck was headed east at the time of the accident. The truck, driven by by 40-year-old Bryan Rhudy, rear-ended a Dodge pickup truck that had stopped at the rear of a column of heavy eastbound traffic. Rebounding off the pickup, the semi truck crossed the median into US-190's westbound lanes and hit first a Nissan Altima, then Roseann Lucidi's Chevy Tahoe.

Lucidi was transported from the scene to Scott & White Medical Center but died several weeks later while still in the hospital's care. The driver of the Nissan Altima, Sarah Brown, was taken to Metroplex Hospital in Killeen with non-incapacitating injuries. The two occupants of the Dodge pickup truck, Copperas Cove residents Dustin and Tiffany Dewald, were not injured according to reports.

Bryan Rhudy was taken to Seton Medical Center in Harker Heights with unspecified injuries. The crash is still under investigation; there has been no mention of what factors might have caused the initial collision. Whatever that turns out to be, though, it sounds like Rhudy didn't leave enough distance between his rig and the pickup to come to a complete stop.

The Importance (and Rarity) of Following Distance

As people navigate your hometown's streets and highways, does everyone drive as close to the car in front of them as possible? That's generally the way traffic moves in urban areas--only a foot or so of space left between bumpers, every driver jealously guarding his or her place against being cut off.

Now think about what happens when one car, just ahead of another, hits its brakes. Is there enough room for the rear vehicle to gradually stop, or is there a very tense moment where it seems like they'll rear-end the leading car because they're following too closely? I know which one I see a dozen times every day.

Most agencies that govern road behavior recommend leaving empty space between one's car and the one in front of it. This following distance is supposedly determined by picking a nearby landmark and passing it two to four "Mississippi" seconds after the car in front of you does. Various safety groups disagree about how many seconds should pass, but that's the general idea.

It sounds great on paper, but anyone who has ever tried to make some room in front of his car knows that the space is filled by another driver almost as soon as it's cleared. At that point the cycle is meant to start over again, reducing speed until following distance is restored, but it doesn't usually work out that way. Make a space and it gets filled because people have places to be, dammit!

Following distance is difficult to maintain, but I think it's safe to say that staying a little further away from a car in front of you considerably reduces the likelihood of rear-ending it. That rings true even more for a semi truck, which requires significantly more space between its front and another car's rear. If it doesn't maintain that space (and too often truck drivers either cannot or do not), too often tragedy follows.

Following and Braking Distance in a Semi Truck

Let's consider the Copperas Cove wreck. We'll generously assume that the Freightliner was carefully adhering to a speed limit of 65mph when the crash occurred. That's probably untrue; experience suggests that people don't obey the highway's posted limit unless they see a cop nearby, but authorities didn't indicate speed as a factor in the crash, and I don't want to condemn Mr. Rhudy for something he didn't do.

Trucks need more stopping distance than cars

To successfully stop before rear-ending the Dewalds' pickup truck, the 65mph Freightliner would have had to start braking over 500 feet from stopped traffic. That's the length of almost two football fields to go from normal highway speed to a full stop. If he stomped the brakes all the way down he might skid to a halt sooner, but that's not guaranteed.

Speculating a bit on the particulars of the multi-vehicle accident, it sounds like Mr. Rhudy had trouble reaching a full stop before he got to the back of a stopped line of cars. Dallas natives might have a different concept of what constitutes "heavy traffic" than a resident of Copperas Cove does, but it's clear from the reports that enough vehicles were on US-190 to create some gridlock.

When everybody slowed and stopped for the traffic congestion, Mr. Rhudy may have been closer than the ideal following distance between himself and the car ahead of him. That's not to say he drove irresponsibly; perhaps, as noted above, he tried to maintain distance and an opportunistic vehicle filled the space he left. Truckers complain about this phenomenon often and many truck crash reports seem to involve this "he cut me off, couldn't help it" narrative.

Since Rhudy's flatbed truck side-swiped the Dewalds' pickup and rebounded, it seems as though he tried to steer clear of rear-ending it when he realized he wouldn't stop in time. Unfortunately, tactics like that don't really work when a large number of cars are all stopped in close proximity.

Proper Braking Distance May Be Complex, But It's a Must

Negotiating highway traffic isn't always simple--far from it. High speeds and split-second decisions (most of us have made a few, be honest) require alert senses and a commitment to preserving everyone's safety. Of course humanity's general nature means that some drivers, entirely aware of the right thing to do, choose the opposite, instead speeding at 120mph and whipping in and out of traffic, ignoring posted laws and common sense with equal aplomb.

Truck drivers cannot afford to be part of this second group. They have a professional obligation to perform their duties with care. They're paid to drive, hauling goods from point A to point B. Their standard of care is raised beyond that of a normal motorist.

It must be tempting to finesse the rules a little to finish a delivery. After all, time bonuses and the lure of the next job await. These incentives might make some truckers forget how important traffic laws are for maintaining safety, and that's how we get 80,000 pound trucks barreling down the road and tailgating two- to three-ton passenger vehicles. They don't maintain adequate following distance, which means they certainly don't have enough braking distance, and when the vehicles ahead of them abruptly stop, what little room there is between them is used up in the blink of an eye.