Turning Accidents

An experienced expert explains the complexities

Author: ned

The Danger Deterrent

By Ned Einstein

Like most fields, public transportation is swollen with studies, both in the U.S. and abroad. Yet some of the most fascinating things seem to be never studied, or rarely studied.

One example of this phenomenon comes from my experience examining more than 80 incidents involving vehicle-pedestrian and vehicle-vehicle incidents. Many of them involved buses or coaches turning.  I learned many unique things from these incidents. Yet some things are still puzzling. One of them is the dozens of incidents that involved buses, motorcoaches or van- and minibus-conversions (to accessible vehicles) making left turns. Yet  I cannot recall a single incident involving a right turn.

The Danger Deterrent

Residing in Los Angeles County from 1980 to 1997, I recall a famous and seemingly-treacherous, un-signalized traffic circle in Beverly Hills. This circle contained three through-streets, or six “spokes:” North Canon Drive, North Beverly Driver and Lomites Avenue — one spoke of which lay almost precisely 60 degrees around the circle from the next. At the point where it faced the circle, each street ended with a mere stop sign — while the risk entering this circle seemed to cry out for yellow-and-purple-striped nuclear warning danger tape. While North Canon was more of a “collector” street than its counterparts, this notion was barely distinguishable to a motorist who neither lived near nor regularly drove through this circle. As a consequence, there were absolutely no clues about which corner’s approaching traffic had the right-of-way.

To a seasoned traffic engineer or transportation planner, a Google-Earth view of this intersection is breathtaking. In the Google-Earth view, the two vehicles shown appear ready to crash into one another. Other than the travel speeds of its cross-streets, this intersection is more intimidating than a Figure 8 racetrack. Reflecting this risk, when first coming upon it, and on every successive occasion, I came to a complete stop. And motorists entering the circle from almost every street hand-signaled one another to either enter first, or to offer thanks for allowing them to. Most of us verily crept across the circle, glancing at the other five spokes and traffic flow within the intersection continuously. Defensive driving on steroids.

I learned what was so astonishing about this traffic circle in 1983, while preparing the City of Beverly Hills’ first transportation plan. What was so extraordinary was that, up until that time, there was not a single accident at this intersection on record. Yet no one in the City’s traffic department had any understanding why. Like myself, several speculated that it was simply because the intersection appeared so profoundly dangerous upon approach that even a compromised motorist (like a drunk driver) would be hesitant to do anything but inch across it — already “reacting,” and ready to brake at any moment.

In between visibly-threatening hazards and risks difficult to see (e.g., black ice) lies a spectrum of risks that bus drivers would do well to be trained to recognize and properly mitigate. One of them is a left turn.

Right to Left Turn Ratios

As I noted above, I have been involved as an expert witness in several dozen left-turn accidents while none involving right turns. One fellow-expert I know has done six cases involving right turns, and feels that there are “many more out there.” Yet, like me, he does not recall ever reviewing an intelligible study about them. I have seen turning addressed in professional drivers’ manuals. But the information and insights were marginal. I do not recall ever seeing anything in these sections about reaction and braking distance — which would typically cover much more distance than for a right turn.

Thinking about this phenomenon a bit more, left turns for vehicles with large wheelbases would seem almost exponentially easier than right turns. Compared to right turns, most left turns are almost sweeping. While “rocking and rolling” should effectively eliminate otherwise blind spots in either, visibility in left turns is still easier: Most of the time, objects with which the bus might collide lie almost directly in front of it.

Another oddity is that right turns into narrow cross-streets require even more of the bus to enter the perpendicular roadway’s oncoming lanes — usually for several seconds. Professional drivers are taught to “rock-and-roll” through all types of turns. But the increased “otherwise-blind-spots” of a right turn are further marginalized by the vehicle’s lower deceleration and acceleration through the turn. Still, given the dimensions and geometry of most right turns, right turns would seem to intensify one’s need to rock-and-roll. However, visibility for right turns is largely through mirrors, doors and side-windows. For left turns, visibility is mostly through the windshield.

A final distinction is that, in making a right turn, the bus driver need worry only about (a) vehicles approaching from the left after passing through a red or amber light, (b) oncoming vehicles turning left, and (c) vehicles too close to the limit line in the oncoming lanes of the right turn. In contrast, a left-turning vehicle has to worry about (a) vehicles coming from the right (against the light), (b) vehicles turning left from the oncoming lane of the cross-street (again, against the light) and (c) vehicles in the oncoming lane traveling straight through the intersection — on the same green light the bus driver has. If left turns are beginning to sound complex and challenging, this is because they are.

Safety and Liability

Despite the size of a bus and the dimensions and geometry of most intersections, the comparative safety of making both types of turns, with a bus, should not be dramatically different. Yet from my forensic experiences, left turns cause exponentially more carnage. Regardless, professional drivers of “common carriers” are held to the highest standard and duty of care. When jurors view the video of a pedestrian waltzing across a bus’ windshield moments before being mowed down, the highest standard and duty of care is the last thing that comes to mind.

Operating below this standard of care is not necessarily endemic to every bus-turn-related collision, even while, in most municipalities, pedestrians have the “right of way.” Of course, in five States (Virginia, Maryland, Delaware, North Carolina and Alabama), this concept is only an illusion. In those States, if the victim is even one percent at fault, the parties overwhelmingly at fault “walk away” from the inevitable lawsuit. But not always. I recently helped one of these victims recover $4.5M in one of these States.

A vehicle or pedestrian who darts into the roadway only seconds before a bus gets there would also seem to be at fault. But this would not be so if the darter or his/her vehicle — poised to dart — was in full view of the professional driver for hundreds of feet before the collision — or should have been. Again, this reality reflects a pedestrian or motorist’s ordinary duty of care in contrast to a professional driver’s highest duty of care. Further, a bus driver is taught and certified in defensive driving — as a necessary requirement for obtaining a commercial driver’s license. A pedestrian or common motorist is taught virtually nothing, although some motorists have at least learned a few dollops from “Driver’s Ed.”

Regarding right- versus left-turn collisions, one factor that might help explain the predominance of left-turn incidents is the fact that the most segments of a buses movement through a left turn is significantly faster. This translates into a problem because of reaction time-and-distance and braking distance. If the driver of a full-size bus or coach with pneumatic brakes begins the turn at 20 mph (which one would almost never do for a right turn), the vehicle will travel almost 59 feet during the driver’s reaction time alone. Then it would take roughly another 32 feet for this vehicle to stop (slightly less if it were lightly-loaded). In simple terms, beginning the turn at this speed, a driver would have to spot an object in front of it more than 90 feet away to avoid striking it.

Given these figures, it would seem like a terrific idea to pull the bus or coach to a complete stop before making a left turn. This is actually the policy of some transit agencies, and regulatory reality in at least one State I know of. Otherwise, in many of the left-turn-related bus-pedestrian collisions I have examined as a forensic expert, the drivers claimed to have seen no one in front of their vehicles until they struck the pedestrian. This lapse may work well in a cartoon. But it does not play well to jurors, who usually perceive the driver as a liar.

Another oddity about turns is related to a bus or coach’s long wheelbase. If the turn is properly made — not turning until the rear axle is aligned with the extended near-side curb line — many buses or coaches would crash through the front window of a building on the far-side corner. In one left turning case I did years ago, a schoolbus driver trying to avoid this fate at an intersection hopelessly too small to accommodate the vehicle turned so prematurely that its rear tires ran over the town drunk literally standing on the sidewalk on the near-side corner. So the dimensions of the bus or coach compared to those of the intersection provide another important reason why it would make sense for a bus driver to come to a complete stop before initiating a turn — and before doing so, to also take a good look around, and perhaps a deep breath.

Some of these problems might be solved by improving or expanding the intersection. Others could be mitigated by routes designed to avoid them. I would not bet on the former happening in a country with 70,000 bridges in need of repair. And I would not bet on the latter where many routes — particularly in schoolbus and transit service — are determined by scheduling software, where live Earthlings have never examined the intersection, and/or where drivers are too complacent or powerless to complain about it.

Always Expect the Expected

The cardinal principle of defensive driving is “Always Expect the Unexpected.” Yet a pedestrian ambling through a crosswalk is hardly unexpected. Nor is a motorcycle or car approaching, and close to, an intersection where a bus turns left in front of it. Perhaps the Smith System should be amended to include “Expect the Obvious.” Because in a courtroom, the employer (and/or its insurance carrier) of a driver who does not do this is likely to pay dearly for it. Particularly when the object struck is captured on a video, the obvious is even more exaggerated. Jurors have to wonder where the bus driver’s mind was while the turn was occurring — if, again, they do not conclude that he or she is simply lying. In three recent cases in which I was involved as an expert, the pedestrian was more than half-way across the crosswalk before being struck. In one case, the driver claimed he did not even notice that the pedestrian’s head made a four-foot-long crack in the windshield right in front of the driver’s eyeballs.

The worst part of all this is obviously that some innocent person was killed or maimed. Otherwise, driver error is only the beginning of what seems to many as a witch hunt for management culprits. Other factors often examined include how and what the drivers were trained, how their performance was evaluated, what their employer’s policies were, and whether the route’s schedule was too tight — among many other aspects of policy-making, planning and management. A savvy attorney and knowledgeable expert will scrutinize every nook and cranny of this employer’s management structure, and its performance. So when a driver makes a simple and seemingly-inexcusable error, his or her employer is likely to be toasted.

Given the magnitude of left-turn killing and mutilation involving buses, it may be time to bring back the old classic, “See Spot Run,” and re-learn the basic idea of “Stop, look and listen!” Drivers who regularly do this usually discover objects they might otherwise strike in time to avoid hitting them. Equally important is it to pay even more attention to those situations that appear to present obvious risks. There is certainly a big difference between Chicago and Cheyenne. But in most places, left turns should be a recognizable hazard all by themselves. Not treating them as such will admittedly  ease the challenges of a tight schedule. But not treating them as hazards also compounds the risk.

As a final thought, monitoring is the Achilles heel of public transportation — certainly in this country, and likely in many or most others. This vacuum leaves drivers marginally- or un-supervised. So one approach to at least reduce the number of these accidents it to grant drivers some input into the route-design process, encourage their feedback about hazardous conditions, and teach them that many left turns are just that. In the current operating environment, drivers seem stuck with the route and its schedule.  Perhaps it is a time to lean on those individuals with the most experience actually making turns. Of course, paying them better would not hurt either. But that is a much larger problem that cannot be addressed from within our industry.

Dancing in the Oncoming Lane

By Ned Einstein

A few months ago, in “The Danger Deterrent” (National Bus Trader, April, 2016), I explored the unsettling dangers associated with vehicles with long wheelbases making left turns. In that article, I mentioned having served as an expert witness in likely two dozen or so left-turn-related lawsuits, yet have never been involved in a case involving a right turn. Superficially, one could only wonder why, since the “rock-and-rolling” necessary to turn right is far greater than that needed to turn left. Plus, most of the victims of left-turning accidents are visible directly through the windshield, often for several seconds before being struck by the nose of a bus or coach.

No reader should deduce from these comments that he or she need not be concerned about right turns, as a safety matter. They have their challenges. The most fascinating it that, other than turns into wide, multi-lane arterial streets or sweeping boulevards, right-turning vehicles with long wheelbases must necessarily spend a few seconds in at least one oncoming lane of the roadway into which they turn. These moments may more accurately be described as a pirouette than, perhaps, a dance step. And as a dance step, it may be more like a samba than a tango. But turning right into a “local” or “collector” street, and certainly any roadway with a single right lane, your vehicle will spend a few seconds dancing in the oncoming lane. So one must ask: Why so few collisions compared to the apparent ease of turning left?

Physics and Directional Stability

Almost every common motorist has, at one time of another, driven up or down a freeway ramp too fast, and experienced the sudden difficulty of keeping his or her car on the road while balancing this feat with the effort to avoid a rollover. Usually, and fortunately, one feels this sensation from the suspension system before one set of tires actually leave the pavement. But turning too quickly on a curve, and sensing the start of a possible rollover, is a scary moment. Is it a moment grounded in science.

In a nutshell, the sharper the arc of a turn, the lower the speed at which the vehicle’s outside tires will begin to leave the pavement, and the lower the speed at which the vehicle will actually roll over. There are plenty of sub-factors involved here: The vehicle’s center of gravity, tire conditions, type of suspension system and rolling resistance on the roadway surface are only among the most obvious. But the general principle remains true. And the degree to which wheelbase length factors into this dynamic is even more complex. Just the same, this reality helps explain why the first rule about turning left, in any vehicle, is to do it slowly. But the second rule is to not do it too sharply. Is it this second rule that creates the dance. This is because, once again, the defining constraint is the arc of the turn. If one wishes to turn faster, that turn must be wider.

Also keep in mind that, because the rear tires of a vehicle with a long wheelbase do not follow the path of the front tires in any proper turn (and much less so in a typically-tighter right turn), such a vehicle’s nose must almost necessarily take a dance-step or two into the oncoming lane. But the wider the turn, the more space this dance step take up in one or more oncoming lanes. And the more time the vehicle spends in this or these oncoming lanes.

Ironically, the driver of a large commercial vehicle cannot have it both ways:

  • If this vehicle creeps around the turn like a disabled snail, and turns when its rear axle is at the optimum position with respect to the extended “near-side” curb-line, then the driver can minimize the space his or her vehicle occupies of an oncoming lane or two.
  • At the same time, slowing to a crawl to minimize this space extends the time that vehicle must spend in this or these lanes.

Philosophers have debated concepts of time and space for centuries. Some have suggested that there is no such thing as time at all; it is merely the illusion of displacements in space. That “other Einstein” proved that as speed (i.e., the rate of an object’s movement through space) increases, time shrinks. In fact, at the square of the speed or light, time ceases to exist. Beyond this speed, time goes backwards — the best “underlying theory” any scientists have come up with to explain a “Black Hole.” Bus and coach drivers need not understand any of this. But they are dealing with a phenomenon every bit as complex during many of the right turns they make.

I do not recall right turns ever described in such terms in any operating manuals I have ever reviewed, even though most bus, coach and heavy-duty truck drivers almost certainly learn about these principles somehow. And most do not experience a rollover or two to get the point. With increasing experience, most drivers would naturally become better at striking a balance between turning speed and turning sharpness (or the arc of the turn). Yet this balance lies between two constraints:

  • One cannot realistically creep around a corner, in a traffic stream, like a snail. At least not if one wants to avoid a few nasty honks from behind, and some minor risk of being rear-ended.
  • At the same time, one cannot sweep across multiple oncoming lanes to create the arc needed to whip around the turn without rolling over.

These constraints necessarily force the driver of a long vehicle to strike some balance. As I have seen precious little written training about it, I can only conclude that bus, coach and heavy-duty truck drivers learn to strike this balance through experience.

Frankly, I think that learning to turn safely is one of the most difficult things a commercial driver must learn. So the typical six weeks of training many bus and coach drivers receive is hardly excessive. This particular maneuver is rendered all the more complex by the fact that not only do the arcs of turns vary considerably, but so too do speed limits. And while most vehicles would roll over while turning right at the speed limit, they often approach the turn at or near the speed limit — even though the industry standard is to slow down considerably, if not come to a complete stop before turning, even with a green traffic signal in the vehicle’s favor. Otherwise, mastering the nuances of turning is all the more important when one recognizes that a vehicle does not usually have the entire dance floor to itself.

Sharing the Dance Floor

One basic highway engineering tool used to control the dance floor (or the intersection) is the “limit line.” On roadways on which commercial vehicles operate, the limit lines behind each spoke of the intersection are often placed far enough behind to allow the nose of a turning bus, coach or large truck to rotate through the intersection-edge of the oncoming lane without striking an oncoming vehicle. Yet this tool only comes into play when vehicles are stopped at it — as they should when the intersection is controlled by a traffic signal or stop sign. (Rules for stopping at crosswalks actually vary from State to State; in some States, for example, one is only required to do so if a vehicle is parked at some point in the intersection.)

In contrast, when vehicles in an oncoming lane are not brought to a stop by one of these devices, signs or markings,  the dance floor is wide open. During his rock-and-roll, a bus or coach driver need not merely “rock-and-roll” to make sure there is no pedestrian to be run over. And he or she need not merely align the rear axle, before turning, to avoid back-slapping or tail-swinging into a parked car. A commercial vehicle driver’s “rock-and-roll” must allow the driver to also peer a reasonable distance down the oncoming roadway to make sure that his or her vehicle does not share the same spot on the dance floor with an oncoming vehicle. (This is known as a collision.) Further, the higher the speed limit on the intersecting roadway, the further down this oncoming lane (or lanes) the commercial driver must see.

Rules of the Road

“Rules of the Road” is a common catchphrase or cliché sloppily employed to cover a range of procedures whose author was usually too lazy or inept to properly define. One often thinks of rules of the road as largely involving courtesies, like making eye-contact with fellow-drivers or -motorist, and perhaps “waving an oncoming or turning motorist on.” Sometimes, such rules are embodied in traffic codes, such as the principle like pedestrians have the right of way, or at an intersection, the vehicle to the right should be allowed to proceed first. I have always found this latter “rule” somewhat confusing — especially when a vehicle is poised at all four (or occasionally more) positions in the intersection. Then there is the rule, commonly embraced in traffic codes, that through-traffic should be allowed to proceed before turning traffic, unless directed otherwise by a traffic signal or Today’s rare live “traffic cop.”

So while there are at least some rudimentary rules that make sense in many common situations, the nuances of making turns (other than with respect to an oncoming vehicle not turning) rarely enter the broad, simplistic rules of the road. In sharp contrast, sharing the dance floor with an oncoming vehicle traveling toward an intersection from a perpendicular street is no simple matter.

Respect and Responsibility

In many previous NBT articles about “Safety and Liability,” I have opined that operating a full-size bus or motorcoach is, in many ways, as difficult as flying an aircraft.  In stating this, it is fair to acknowledge that almost any idiot can be taught to lift off in an aircraft with minimal training. The challenge is landing it (as opposing to crash-landing it). In other ways, operating a bus or motorcoach is more difficult. One example is that pilots have little responsibility for passenger management, and  since 9-1-1 (at least in theory), cockpit doors are even closed to passengers. So not only should there be no threats and no acts of violence, there should be no distractions.

As far as turning, I will admit that this seems more difficult for an airplane, particularly given the speeds at which they travel, and the balance they must maintain in order to not quickly fall into a dive. At the same time, the arc of a plane’s turn is exponentially wider than that of a ground vehicle turning on a roadway. Plus, if the pilot is capable, an aircraft can roll over multiple times with precious little risk (assuming this is done with the plane still in the air).

Regardless of whom is more deserving in this comparison (a pilot or a commercial driver), I have enormous respect to the skills of a good bus or coach driver. E-N-O-R-M-O-U-S.  But to deserve this respect, that driver must take the responsibility to master the maneuvers described above.

In her popular recording “gone platinum” long ago, Aretha Frankly belted, “R-E-S-P-E-C-T. Tell you what it means to me.” What it means to me is, that to deserve my respect,  a commercial driver must accept and embrace the responsibility of mastering the challenging skills noted above. If not, the most important rule-of-the-road should be: Stay off it.

The formula for the force of two colliding objects sloppily approximates the inverse square of their respective masses. So a 1000-lb. automobile colliding with a 40,000-lb. bus absorbs not 40-times the impact that the bus does, but closer to 1600 times that impact. When the loser in this match is made of skin and bones rather than steel, glass and rubber, these dynamics are greatly exaggerated. So the operators of such vehicles need be more than both skilled and careful.  They need to be very skilled and very careful.

If a driver fails to master these skills, and/or fails to exhibit the degree of concern warranted — notwithstanding a third party compromising his or her ability to properly exercise these skills — he or she is going to lose my respect quickly. Far more importantly, he or she is likely to lose the respect of some jury, and along with it, the insurance carrier of that driver’s employer is likely going to open its wallet, and open it wide. While two steel vehicles colliding may often result in a mere fender bender, such vehicles do more than bend a fender when they strike a pedestrian. When a 43,000-lb. motorcoach does this, the affair rarely has a happy ending.

Turning Accidents

Coming Soon!

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