The Life-Altering Reality of Semi-Truck Stopping Distances

    Newton’s second law of motion states that the force of an object is equal to its mass multiplied by its acceleration. With respect to traffic accidents, this means that a heavy vehicle traveling at a fast rate of speed will be capable of hitting another vehicle with an impact serious enough to cause life-threatening personal injury to others. Semi-trucks weigh significantly more than the typical passenger vehicle. The average semi-truck can weigh upwards of 80,000 pounds when fully loaded with cargo, compared to approximately 4,000 pounds for a standard passenger car. This difference leads to vast discrepancies in braking distance between the two vehicles.

    Understanding Semi-Truck Stopping Distances

    Compared to a normal passenger vehicle traveling at the same speed, large trucks like semi-trucks take much longer to come to a complete stop, even in ideal conditions. The total amount of time it takes a semi-truck to make a stop depends on a number of factors, including the overall weight of the vehicle and the load it is carrying in its trailer, as well as the conditions of the roadway and if the driver had time to prepare for the stop or was forced to engage in emergency braking maneuvers due to unforeseen activity on the road.

    According to the Federal Motor Carrier Safety Administration (FMCSA), a normal passenger vehicle traveling at 65 miles per hour will need approximately 300 feet to come to a complete stop. However, a fully loaded truck driving at that same speed will need about 600 feet to come to a complete stop. In other words, the semi-truck in this scenario will need about twice as much room in order to safely come to a complete stop when compared with the average car.

    Factors That Influence the Stopping Distance of a Semi-Truck

    PLG Blog Images (71)

    Many different factors can account for the variation of semi-truck stopping distances, as well as the severity of any injury that may result from an accident. For example, the reaction time of drivers can play a major role in how quickly a potential threat is responded to on the roads. For both passenger vehicles and trucks, it typically takes a driver about 1.5 seconds to register a dangerous situation and apply the brakes. This reaction time can be impeded if the driver is under the influence of drugs or alcohol or if they are otherwise distracted while behind the wheel.

    The weight of the vehicle is another major factor that determines how long it will take a semi-truck to come to a complete stop. If the truck is carrying a heavy load, it will take longer to come to a stop than an empty truck. Heavier loads also cause semi-trucks to accelerate more quickly when going downhill, requiring extra braking power when needed.

    Speed may seem like an obvious factor that impacts the stopping distance of semi-trucks, but it cannot be ignored. No matter the size of the vehicle in question, the faster it is going, the longer it will take to come to a complete stop.

    Finally, the nature of a semi-truck’s braking system can impact its braking distance. While most passenger vehicles are equipped with hydraulic brakes which use liquid to shorten stop times, semi-trucks often have air brakes that take more time to work. When a truck driver first applies an air brake, air builds up across the length and breadth of the vehicle. When this air buildup is complete, the brakes begin to slow the truck. This braking process takes more time, which can impact how long a truck driver needs to prepare for a stop.

    If you include weather and road conditions, this is another factor that can often exacerbate the already slow stopping time of a semi-truck. If the roads are wet or icy, it’s even more difficult for a trucker to safely bring the large vehicle to a full stop.

    Common Examples of Accidents Involving Semi-Trucks

    PLG Blog Images (53)

    The stopping distance required by semi-trucks is just one of many examples of factors that can contribute to major truck crashes. We have covered many of them in our blog recently, but let’s go over some of the major examples to be aware of. Keep in mind that some of these common causes could potentially go hand-in-hand with the stopping distance issue, creating an even more dangerous situation.

    • Blind spots contribute to accidents between commercial trucks and passenger vehicles in a number of ways. One common cause of accidents occurs when vehicles are following each other too closely, whether in front or behind a semi-truck. Semi-trucks need a much longer stretch of road in which to slow down, meaning any motor vehicle that stops abruptly in front of a semi-truck may not be able to avoid being hit from the rear. On a similar note, cars that follow too closely behind a semi may not be ready to brake at the same frequency that truck drivers do, leading to a collision.
    • Truck driver fatigue is another common cause of accidents. Fatigue can lead truck drivers to make careless mistakes including not completely assessing their blind spots for signs of danger. Truck drivers are expected to sit for prolonged periods of time, often at hours of the day that do not align with their normal sleep schedules. This can cause impaired judgment, leading to accidents that cause injury on the road.
    • Sudden lane changes constitute another common cause of accidents between semi-truck drivers and passenger vehicles. When either party commits a sudden lane change, it can cause a change reaction of reflexive maneuvers that can cause drivers to lose control of their vehicle. Truck drivers should take prolonged precautions to ensure there is not a vehicle in their blind spots before executing a lane change.
    • Finally, distracted driving can cause accidents between semi-trucks and passenger vehicles. When a truck driver is distracted by their phone or something else, it can lead to absent-minded decision-making that rarely includes due attention to the truck’s blind spots.

    In all of the examples of semi-truck accidents mentioned above, the ability of the truck to come to a stop will impact the severity of the accident. For a truck driver, perhaps nothing is more stressful than having to make an emergency maneuver due to either an unexpected event on the roadway or their own negligent behavior while behind the wheel.

    Assessing Negligence After an Accident


    When the driver of a passenger vehicle is involved in an accident with a commercial vehicle like a semi-truck and suffers any kind of injury as a result, it can have an extremely traumatic impact. Because of that trauma and the expenses that are typically involved in these accidents, most people want answers. It’s common to want to know more about pursuing legal action in order to recover compensation for any damages incurred as a result of the accident.

    To successfully recover compensation, a plaintiff and their legal team must be able to prove to the courts that the semi-truck driver was acting in a negligent manner in the events leading to the accident. For example, if the driver was not properly checking their blind spots in the moments leading to crash, this can likely be considered negligent behavior and therefore the driver and/or their company may be liable for compensating the injured victim.

    Many commercial trucking companies utilize two-way dashboard cameras (i.e. dash cams) in the cabins of their semi trucks in order to increase accountability. In the case of an accident, these cameras can be used as evidence to determine whether or not the driver was being negligent. In addition, drivers of passenger vehicles may consider purchasing a dash cam of their own, especially if they frequently share the road with a high number of semi-trucks. In the event of an accident, the evidence gained from these devices can help courts quickly determine fault.

    Illinois uses a doctrine of fault determination known as “modified comparative negligence.” Under this system, an injured party can only recover damages if they are less than 50% responsible for the events that ultimately lead to the accident and subsequent incursion of personal injury.  If they are deemed by the court to be 50% or more at fault for the accident, then they will automatically forfeit their ability to recover compensation from the defendant for any expenses related to the incident.

    Professional Legal Counsel in Chicagoland

    For years, the truck accident attorneys at Palermo Law Group have been helping victims of accidents with semi-trucks in Oak Brook and throughout Chicagoland as they fight for the compensation they deserve. Contact Palermo Law Group today for a free consultation.



    Mario Palermo is the Founder and Lead Attorney at Palermo Law Group in Oak Brook, Illinois. For the past 26 years, he has worked tirelessly to help injury victims and their families in their times of need. He is a seasoned authority on civil litigation, and also a member of the Million Dollar Advocates Forum, a prestigious group of trial lawyers who have won million and multi-million dollar verdicts and settlements. Mr. Palermo has been named a “Leading Lawyer” by his peers in 2015, 2016, 2017, 2018, 2019, 2020, 2021 and 2022.

    Request a Free Legal Consultation

    Recently Published

    Recent Outcomes

    $1.3 Million

    Mr. Palermo obtained $1.3 million dollars for an airline employee who was injured on the job.


    Palermo obtained $800,000 for the family of 63-year-old woman who died after gallbladder removal surgery.


    Palermo obtained $400,000 for a 28-year-old woman from Aurora that was the victim of a hit-and-run.