Commercial Motor Vehicle Traffic Enforcement

Targeting Crash-Causing Violations

Back    Table of Contents    Next

Serious moving violations are defined in the commercial driver’s license disqualification statute or regulation. These violations can cause serious crashes and can lead to driver disqualification. Serious moving violations by CMVs will be reviewed in this module. However, they are not exclusive, since both commercial vehicles and non-commercial vehicles are subject to basic highway safety traffic laws that are too numerous to cover in this guide.

Speeding is perhaps the most common violation. Law enforcement agencies receive numerous calls every day from citizens complaining about trucks speeding through residential streets, speeding on the open road, and not reducing speed at school crossings, blind intersections, business districts, and railroad grade crossings.

While State speed limits generally apply to both commercial and non-commercial vehicles, some States restrict large trucks, certain types of buses, vehicles towing trailers, and trucks transporting hazardous materials. All States have statutes that address reducing speed when specific special conditions are present, such as at school zones, adverse weather conditions, steep down-grades, sharp curves, or other situations where traveling at the posted speed limit becomes unsafe and threatens the safety of others.

Law enforcement agencies receive numerous calls every day from citizens complaining about trucks speeding down their residential street, on the open road, at blind intersections, in business districts, at railroad grade crossings or not reducing speed in school zones.

Following too closely is the second most frequent complaint. Following too closely, or tailgating is a common violation. However, when the driver of an 80,000 pound truck tailgates a 2,500 pound automobile, the potential for a disaster is much greater. The average stopping distance for a loaded tractor-trailer traveling at 55 mph is 196 feet, compared with 133 feet for an automobile. Adverse highway conditions, such as rain, ice, snow, other debris, or mechanical conditions, such as faulty brakes, air loss, or bad tires, increase the potential for a crash. These problems increase when the CMV is transporting hazardous materials.

A common complaint from CMV drivers is that drivers of passenger vehicles cut in front of them. Officers should observe the CMV for a distance and allow the driver time to compensate for this before citing the CMV for following too closely.

Improper lane changing is another frequent violation. This often occurs under two circumstances: in heavy traffic flow where commercial vehicle drivers squeeze their vehicle between automobiles when overtaking slower traffic; or on the open highway and traveling at full speed, when CMV drivers fail to slow down for vehicles as they approach from the rear. This violation also occurs at high speed merge locations when the commercial vehicle driver fails to accurately gauge the vehicle’s position and speed during the merge maneuver. In addition, this violation also occurs when other vehicles are traveling in the commercial vehicle’s blind spot. This demonstrates the importance of signaling before attempting to change lanes.

Reckless driving can be described as the “wanton, willful disregard for the welfare and safety of another person or property.” This violation requires the establishment of the wanton and willful disregard element. Some prosecuting attorneys and judges require a minimum of three concurrent serious moving violations to establish this element, while others consider knowingly operating a vehicle with faulty equipment, such as inoperative brakes, as being reckless. It is the traffic enforcement officer’s responsibility to know what the courts deem reckless, as well as the agency’s policy. This knowledge is essential if the driver is to be properly cited.

Following too closely or tailgating is the second most frequent complaint and is an ongoing violation of all drivers.

Improper turning is the act of failing to yield right-of-way to oncoming traffic or failing to stay in the prescribed lane. These violations occur almost instantaneously and require focused attention to all circumstances pertaining to the event. Tractor-trailer combinations, buses, and longer single unit commercial vehicles require much more room to turn than automobiles. When making right turns, these larger vehicles will move either partially or entirely into the adjacent left lane before they start the turn. This maneuver is necessary to afford the driver the turning radius needed to complete the turn. Often, when the driver moves to the left and then starts the turn, drivers of automobiles will attempt to pass on the right and usually end up being struck by the trailer or colliding with the passenger side of the CMV. The positioning of the CMV prior to and during the turn in relation to its overall length must be considered when dealing with this type of incident. If the driver was appropriately positioned to make this maneuver safely, the violation would be committed by the driver of the automobile. However, if during the turn the truck driver encroached into the right-of-way of approaching traffic, a violation would charged to the truck driver.

Other frequent CMV complaints are improper lane changing, reckless driving, improper turning and driving under impairment.

Driving while impaired involving a CMV, particularly one transporting hazardous material, is a catastrophic event seeking a time and place to happen. Officers need to be constantly alert, both day and night, for actions and indicators such as driving too slowly, failing to stay within a single lane, careless/reckless driving, or any other behavior that would indicate the possibility of an impaired CMV driver. CMV drivers are considered impaired at 0.04 percent BAC. Officers should observe the actions of the driver during the initial vehicle stop for additional indicators of impairment. Other indicators to watch for are:

After the officer determines, based on the CMV driver’s mental state, driving, physical appearance, and actions, that further investigation is necessary, standard field sobriety tests should be administered. Additionally, the officer needs to assess the possibility of a medical condition that may lead to reactions that mimic impairment (e.g., diabetic shock).

When the officer determines that there is sufficient probable cause to arrest a CMV driver for DWI, the procedures are the same as for any driver of any other type or class of motor vehicle. The statutes applicable to implied consent, chemical/breath testing, and the type and number of tests administered will determine the appropriate course of action the arresting officer should take.

In the event the officer cannot obtain sufficient evidence of DWI and the driver appears to act in a normal manner, a trained officer or certified CMV inspector should be summoned to the location. This officer can review the driver’s hours-of-service records and other related documents to determine if the erratic driving was the result of driver fatigue, perhaps caused by an hours-of-service infraction.

When the officer determines that sufficient probable cause is present to arrest a CMV driver for DWI, the procedures are the same as for any driver of any other type or class of motor vehicle.

Parking on the shoulder of controlled access or other roadways by CMV drivers can be a significant contributing factor to injury or fatal crashes. The main reason CMVs are parked on highway shoulders and other unsafe locations is mechanical breakdown. However, drivers are often in need of rest, particularly in the early morning hours, and may not know the locations of nearby rest areas or truck stops. Also, deliveries scheduled for early morning often cause a driver to park at the city limits or near the delivery point to wait for the delivery location to open.

Many crashes involve vehicles striking trucks parked on the shoulder. Studies indicate that CMVs were involved in the major portion of these crashes and that they occurred primarily between midnight and 6 a.m. Alcohol involvement or fatigue were the two main causes noted.

Officers should be aware of the potential for serious crashes associated with CMVs parking on highway shoulders. Providing assistance for disabled vehicles and informing drivers of safe parking areas will contribute to a reduction of CMV crashes.

Parking on the shoulder of controlled access or other roadways by CMV drivers can be a significant contributing factor to injury or fatal crashes, although the main reason CMVs are parked on highway shoulders and other unsafe locations is mechanical breakdown.

Violating other commercial motor vehicle laws. Your county or city may have laws restricting the times of day the CMV may use specific roadways or designate specific truck routes in urban areas or prohibiting CMV traffic altogether; providing weight, height and width restrictions, weather conditions, and hours of operation; requiring escort or pilot vehicles, sometimes requiring height poles, lights, radio communications, and personnel to have weapons to protect the load; and, limiting hazardous material or requiring placards, lights, etc. In these instances, a permit is often required by the State. Be aware that some Department of Defense and Department of Energy movements are not subject to certain traffic law regulations, and are often accompanied by armed escorts. Officers need to contact these agencies so that their dispatcher can, in turn, call the driver to advise him on the procedure for the stop.

Generally, CMV drivers are required to hold medical certification. Check your State law for applicability.

Stopping at railroad grade crossings. Drivers of CMVs that are transporting hazardous material in quantities requiring placarding, or any bus transporting passengers are required to make a complete stop at all railroad grade crossings. After stopping and looking for approaching trains, drivers may then continue across the tracks without shifting gears.

All States have statutes requiring CMVs of this type to stop at railroad grade crossings. When officers observe a CMV displaying hazardous materials placards and it fails to come to a complete stop at a railroad grade crossing, a violation has occurred and the stop should be initiated.

After stopping the placarded CMV in a safe location, officers should obtain the shipping papers from the driver and note the commodity transported on the citation, e.g., gasoline, sulphuric acid, compressed gas, poison gas, chlorine, or check the "HM" box on the citation, if provided.

Officers should be aware of state statutes that govern the movement of placarded CMVs and buses at railroad grade crossings.

Back    Table of Contents    Next

Official U.S. Department of Transportation insignia with triscallion symbol Logo of National Highway Traffic Safety Administration Logo of Federal Motor Carrier Safety Administration