Buses and Bikes – Mass, Visibility and Unfair Fights: On Vehicle-Pedestrian and -Bicycle Collisions

In those rare instances where the safety of transportation modes can be compared statistically, bus riders fare several decimal points better than bicycle riders. The risks associated with motorcycles are “off the charts.” The Figure below illustrates these comparisons for “home-to-school” trips – trips that comprise 15 percent of all transit trips and 96 percent of all school bus trips.

[Insert Figure 4-1: Safety by Mode]

As safe and cozy as bus passengers are for their riders, when they or others cross in front of or behind the bus, they do not fare well compared to crossing near other modes. A study conducted between 1994 and 1997 by the New York State DMV calculated pedestrian fatalities per million miles traveled for personal-occupant vehicles, trucks and buses. Buses were involved in noticeably more:

  • cars are involved in 1.36
  • trucks are involved in 3.21
  • buses are involved in 8.80

While statistics for vehicle-bicycle fatalities are harder to come by, the Figure above suggests that bicyclists fare slightly better than pedestrians, in general. This is likely due to their acceleration and maneuverability, compared to walking: A bus cornering slowly may still accelerate faster than a pedestrian, while a bicycle can generally zoom out of harm’s way before the bus makes contact. Even so, bicyclists and motorcyclists experience their fair share of incidents.

Force, Mass and Acceleration

In science class, we were taught that mass equals force times acceleration. Yet, while the mass of a bicycle or motorcycle and its occupant are a fraction of the mass of a full-size bus or coach, their collision can produce a surprising amount of force:

Traveling at full-speed with no appearance of ever braking, a 78-year-old motorcyclist rear-ended an idling transit bus whose driver had failed to pull to the curb. Presumably, the bus’ parking brakes were not engaged: The motorcycle smashed into the rear cap so hard that it not only ruptured the bus’ cooling system, but knocked the 38,000-lb. bus forward twenty feet. While largely not his fault, the bus driver felt so badly about the incident that he committed suicide.

Visibility and Cues

Viewed from above, the sector of visibility depicted in an exterior, side-view mirror resembles a 30-60 triangle emanating rearward from the mirror. Of course, attached to the body of the bus or coach, this view swings around with the bus itself:

  • Instead of pulling parallel to the curb, a transit driver pulled the nose of his bus to the curb, such that the body of the bus posed a sightline blockage between the driver and vehicles approaching it from the rear. So when the driver began to pull out, he did not see a bicyclist approaching his bus from behind. As the cyclist neared the roaring rear engine and the bus began pulling out, she pedaled into an adjacent lane – where she was immediately struck by a car passing the bus. In her deposition testimony, the bicyclist described the intersection by citing things she observed while she was in the air!

Long Wheelbase Cornering

Professional bus, coach and truck drivers are well-aware that their vehicles do not turn in a circular fashion – particularly with tight, right turns – but instead, their bodies pull straight-forward until their rear axles clear the perpendicular, extended curb-line of the near-side of the intersection. At that point, the driver steers the bus sharply to the right, and once reoriented after this clockwise rotation, the front of the vehicle “drags” the rear around: The rear axle takes a somewhat linear “short-cut,” and the curb-side of the bus or coach swings back toward the corner like a steel, glass and rubber wave:

  • When the light turned green, a bicyclist watched a school bus pull straight out into the intersection. Just before the front cap reach the halfway point – from which its driver would have turned sharply to the right – the bicyclist assumed that the vehicle would be traveling straight through the intersection, and entered the intersection alongside the bus. Because bicycles can accelerate so rapidly compared to a bus or coach, the cyclist reached the mid-point of the bus before its “wave” began moving backwards toward the cyclist. The cyclist never had a chance: His bike was crushed like so many strands of steel, plastic and rubber, and its rider, as Mark Twain put it, became a mass of protoplasm and buttons.

Vision and Visibility

Considering the magnitude of incidents where the bus itself runs over pedestrians (see “Just Being There” in NBT, February, 2008), the positioning of bike racks on the front bumper – where the top of the bike poses a sightline blockage through the lower band of the windshield – seems foolhardy, even though it is the norm. Far better approaches have been demonstrated.

[See Figure below: Bike Rack on Rear Cap of Ameritrans]

While poorly-positioned bicycles can operate as sight-line blockages, bicycles themselves are not always spotted when they should be:

  • At the outset of dawn, a shuttle bus entered a tunnel with narrow lanes and struck the left handlebar of a bicyclist pedaling through on the narrow shoulder outside the fog line. Several days afterwards, when the bus driver’s eyes were examined, the physician found him to have cataracts in both eyes.

Relative Mass and Relative Fault

Because of a bus or coach’s exponentially greater mass, passengers on board during these collisions fared quite well. In most cases, they barely felt the collision. But their drivers, and particularly their drivers’ employers, fared far worse in the inevitable lawsuit.

Largely because of their speed and maneuverability, bicycles may be more difficult to spot than pedestrians, and they may operate as moving targets. However, the U.S. legal system rarely gives the larger, striking vehicle a free pass. Part of this reality is institutional: Operators of public transportation vehicles are generally considered “common carriers” and, as such, are held to “the highest duty or standard of care.”

Part of this disproportionate liability also has to do with visibility. A bus or coach driver sits relatively high up “on the throne,” has a panoramic windshield, an ergonomic driver’s seat and tilting/telescoping steering column, and at least five mirrors (school buses have seven). Yet even with all this equipment, bus and coach drivers are taught to “rock and roll” as their vehicles move about – bobbing their heads forward, sideward and rearward to circumvent any blind spots that might emerge during segments of their vehicle’s movement. So when they fail to spot the inevitable target, their failures are rarely excusable.

Shots in the Dark

As part of both Federal and state law, commercial vehicle drivers in every state must have their vision tested. However, night vision is generally not tested, and this capability generally fades with age: According to one “pop stat,” a driver at age 50 possesses only half the night vision he or she had at age 25. Similarly, the shape of our eyeballs also changes, leaving those with normal eyesight far-sighted, and those already far-sighted more far-sighted. Experience may offset the physical deterioration to a limited extent; how much so is hard to guess.

Perhaps because of their fragile mass and the vulnerability that accompanies it, bicyclists often receive considerable sympathy in lawsuits after being struck down by a twenty-ton bus or motorcoach. The bus or coach almost always wins the battle on the roadway. But in a courtroom lit up by scores of 150-watt bulbs, leaving the trial unscathed is often little more than a shot in the dark.

Publications: National Bus Trader.