TRUCKIN’ ON: Reducing the danger of Trucks and other Large Vehicles

Trucks are only 4% of vehicles in the United States but cause about 7% of pedestrian fatalities and 11% of cyclist fatalities. The disparity is even higher in urban areas – a London analysis found that the 4% of vehicles that were trucks were involved in nearly 53% of cyclist fatalities. In Boston, 7 out of 9 cyclist fatalities in 2012-13 involved trucks or buses. Many of those deaths were preventable.


Of the pedestrians and cyclists killed by trucks in the US, one-quarter and one-half, respectively, are first hit by the side of the truck, then fall under the rear wheels and are crushed as the vehicle turns. Almost all of those deaths were preventable.

There are a variety of reasons for the deadliness of these interactions: individual behavior, the legal and cultural decision-making context created by law and regulation and public campaigns, the design of roads and intersections, and the nature of the vehicles themselves.  Paying attention to these will help prevent accidents. But no matter how careful we are, some accidents will happen and it is inexcusable to not implement the proven, relatively easy and inexpensive way to reduce the severity of the resulting injuries: putting side-guards on trucks and wheel-guards on buses. It’s time to move.  


  • Side-guards and Wheel-guards save lives and should be both installed on city-owned vehicles and required on trucks used by vendors for city contracts. Use of sidewalk “loading areas” might also be restricted to trucks with side-guards. Side-impact-with-truck pedestrian deaths decreases by 20% in the UK, and cyclist fatalities dropped 61% after sideguards were required there. Germany had a confirming 40% decrease in cyclist deaths.
  • It is vital that the height of the side guard from the street be small enough to effectively prevent roll-unders by children as well as adults – for example, the side guard should be no higher than the lowest part of the truck and cab body or a maximum of 14 inches, whichever is lower.
  • Municipalities should also explore the accident prevention benefits of installing additional blind-spot mirrors or cameras on its trucks, as well as side-of-truck outside turning blinkers and audible alarms to warm pedestrians and cyclists that a truck is turning.
  • The Public Schools should be urged to work with the municipal Bikes Program to expand access to bicycle skill and safety training in Elementary and Middle schools, as is already happening in Cambridge.
  • The city’s Traffic and Public Works Departments should be required to aggressively implement its Complete Streets and Bicycle Network plans which will improve the safety and functionality of our streets for pedestrians, cyclists, and car occupants.
  • The city should urge the state to strengthen Commercial Driver relicensing requirements.

INDIVIDUAL BEHAVIOR: Calming the Irrational

Everyone is occasionally careless or mindless or distracted or just makes a mistake, no matter how much they know or have trained. But knowledge and preparation helps. Adding to the problem is the low level of training and licensing requirements for vehicle drivers. Federal requirements for a license to drive an 80,000-pound semi are just 10 hours of classroom training and a driving test in a parking lot. Even worse, renewing a state-issued Commercial Vehicle Driver’s License requires little more than an eye test and an updated background check.   It is unclear how many current truck drivers are aware of the 2008 changes in Massachusetts’ vulnerable user protection laws or the new regulations concerning parking in bike lanes. More worrisome, despite new US Department of Transportation regulations limiting the number of continuous hours drivers are allowed to put in and the maximum weight allowed in various vehicles, companies in this deregulated industry continue to push drivers for increase productivity – meaning faster speeds, heavier loads, and greater exhaustion from the hours of unpaid loading work. As anyone who passes all the closed “weigh stations” along the Interstate already knows, enforcement of these trucking laws is very spotty.

Pedestrians and cyclists also do stupid things. In the Netherlands, bicycle skills are a regular part of elementary school physical education classes. (Driving tests and renewals are much more stringent as well.) While Cambridge now includes bicycle skill and safety modules in 5th grade, Boston doesn’t. In fact, across the USA, not only is this topic almost never addressed, but under pressure to improve standardized academic test scores, many schools have all but eliminated Physical Education entirely – undermining not only the long-term health but, ironically, the ability of high-energy children to sit still and learn.


In the rush of the moment we often operate on instinct rather than reasoned logic. But even our instinctual reactions are shaped by the decision-making context. Corporate productivity pressures and work rules are the most immediate context shaping driver decisions. Company policies are themselves largely shaped by insurance regulations and the legal/regulatory climate. The most common are limits on the times and days that trucks are allowed to unload on city streets, bans of trucks over a certain size from turning on to narrow streets or in particularly dangerous intersections. The presence of a “vulnerable road user protection” law – in which whoever can cause the most damage is required to be the most careful – would be a powerful consciousness-raiser.

Just as influential, on both the conscious and instinctual levels, is public awareness of civic campaigns such as those led by Mothers Against Drunk Driving, the media headlines about distracted driving, local “Twenty is Plenty” efforts to slow traffic, and public efforts such as New York City’s Vision Zero. Even when we’re not paying attention, these messages are in our heads.


Public Health provides many insights about what shapes human behaviors.   For example, giving people small plates leads them to take and eat smaller portions while not feeling any less satisfied than if served bigger helpings. On the road, the design and condition of the streets and intersections changes our perceptions. We tend to drive as fast as the pavement allows us to feel comfortable going regardless of the posted speed limit.

Wide lanes, gentle curves, no sight-line obstructing hills, limited entering/exiting locations with long ramps, no visual distractions other than large and uniform directional signage, and the absence of slower or more vulnerable traffic – all makes us go faster.   We slow down when driving on narrow lanes – either physically narrowed (through road and lane diets, separated cycle tracks, or corner curb “bulb-outs”) or just visually narrowed (with adjoining trees and “distracting” activity on the sidewalk).  A recent report from the US Department of Transportation stresses the benefits of road diets for car occupants as well as pedestrians and cyclists, pointing out that “road diets reduce all traffic crashes by an average of 29%.”

Putting Interstate-influenced roads into urban settings, where trucks are the most likely to be around pedestrians and cyclists, turns out to be a prescription for disaster. Arterials, the large collectors that are the city version of highways, are the most dangerous streets. According to the Journal of the American Planning Association, “Each additional mile of arterial…was associated with a 9.8% increase in motorist crashes…. examinations of the spatial distribution of pedestrian-[injuring] crashes show that they cluster along urban arterials…”

The latest safety-promoting intersection designs in Holland combine all these elements, with wide sidewalks and narrowed crossings around the perimeter, cycle tracks inside those, large bulb-outs requiring slow and careful turns for cars in the middle.

LESS DANGEROUS VEHICLES: Prevention and Protection

Accidents are much less likely to occur if the people involved are aware of each other’s presence. There is simply no excuse for a bicyclist to not have a rear view mirror of some kind, or for night-riding bicyclists to not have blinking lights and light-colored or reflective clothes. Similarly, trucks should be required to have warning stickers (“if you can’t see my mirrors I can’t see you”), auto-activating side-mounted turning blinker signals similar to the ones now required to be on European cars’ outside mirrors (it’s impossible to know if a truck is turning once you’ve passed its rear), and perhaps even audible warning sounds announcing that the truck is turning to the right into its blind spot.

In fact, in addition to having a long stopping distance, trucks have huge blind spots directly below in front, in back, and along the sides –especially on the right side.   Drivers simply can’t see approaching pedestrians and bicyclists in those areas.   And when a large truck turns right it “drifts” in ways that are hard to anticipate but squeeze the person until, possibly, she is hit by the truck side. Trucks need to be equipped with some combination of special convex mirrors to see the sides, crossover mirrors for the front, Fresnel lenses for the immediate right side, 360-cameras, and perhaps even proximity sensor alarms that blink or ring if someone is too close when a turn begins. It all sounds complicated, but it’s relatively cheap and a recent study by Transportation for London found that nearly all the participating drivers found the devices easy to use and very effective.

Injury is one thing. Death is another. Bike helmets don’t prevent accidents, but they do usually reduce the severity of any head injury that occurs. However, a helmet won’t save anyone thrown under the rear wheels of a truck. Sideguards will. Sideguards are railings or smooth mesh or solid panels bolted on the lower sides of a truck to cover the gaping space between the front and rear wheels. There was a 61% decrease in cyclist fatalities and a 20% decrease in pedestrian fatalities in the UK in side-impact crashes with large trucks after their national sideguard law was implemented. Germany had a confirming 40% decrease in cyclist deaths.

Sideguards work. The UK, the European Union, Japan, China, and Brazil all have mandatory sideguard laws. In the US, Portland, Washington DC, Boston, Cambridge, Somerville, Newton, and NYC are all implementing or studying various approaches, although none are as comprehensive as the European requirements, which apply to all vehicles over 7,700 pounds. The bill pending in the New York State Senate, would only require sideguards on trucks over 26,000 pounds, the same high weight threshold above which New York State requires trucks have convex crossover mirrors for the front blind spot.

Boston’s DPW has begun experimenting with side guards, and deserves praise for taking that initiative. However, the height of the side guard from the street needs to be small enough to effectively prevent roll-unders by children as well as adults. It might be good to specify that the side guard should be no higher than the lowest part of the truck and cab body or a maximum of 14 inches, whichever is lower.

There are secondary benefits as well. Side guards reduce damage from contact with other vehicles and objects. And similar devices widely used in Canada, called side-skirts, are installed primarily because they provide a 5-7% improvement in fuel economy.

Truck-pedestrian/cyclist accident reduction is a rapidly evolving field of practice.   We have to stay flexible as experience grows and the tools change. But that is not an excuse for inaction. We should not wait until suits by bereaved families lead to judgments against the shipping industry. Every pedestrian knows they stand no chance if a car driver doesn’t stop. Every bicyclist knows that the next unexpected death could be their own. Experimentation is fine. Doing nothing isn’t.


Thanks to Alex Epstein and his colleagues at the Volpe National Transportation Systems Center who have brought side guards to the attention of US advocates.


Previous related blog postings include:

> TIME TO GET SERIOUS ABOUT SAFETY: Looking Beyond Traffic Lights
> THE RIGHT TO BE ON THE ROAD: When Bicyclists Have To Pull Over, When Cars Can Pass
> INTERSECTION CAMERAS, TERRORISM, AND TRUST: Fears and Memories Across the Generational Divide
> VULNERABLE ROAD USERS (VRU) PROTECTION LAWS: “Whoever Can Do The Most Damage Has To Be The Most Careful”


posted in TRANSPORTATION HEALTH and SAFETY by Steve Miller


1 Comment to "TRUCKIN’ ON: Reducing the danger of Trucks and other Large Vehicles"

Steve Miller wrote:

  1. I just was sent an article about the safety impact of smaller, European-style delivery trucks. Maybe we should be setting size limitations (perhaps by banning trucks larger than a certain size from unloading during daytime hours.

    “How Super-Small, European-Style Delivery Vehicles Could Make U.S. Streets Safer” —


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