Concept of Operations and 

Voluntary Operational Requirements 

for 

Lane Departure Warning Systems (LDWS) 

 On-board Commercial Motor Vehicles 

July 2005 
i 

Foreword 

The Federal Motor Carrier Safety Administration’s (FMCSA’s) safety goal is to reduce the 

number and severity of large truck fatalities and crashes. During the last several years, FMCSA 

has collaborated with the trucking industry to test and evaluate several on-board safety systems 

for commercial motor vehicles to increase the safety and security of all roadway users. FMCSA 

is now promoting voluntary adoption of these systems within trucking fleets by initiating steps to 

work closely with the trucking industry to define vendor-independent, voluntary requirements. 

The purpose of this document is to relay a better understanding of the functions of on-board 

safety systems for vehicle stability and to provide insight into the safety and efficiency benefits 

of using the systems. This document describes the concept of operations and voluntary 

requirements for Lane Departure Warning Systems (LDWS) for large trucks greater than 10,000 

pounds gross vehicle weight rating (GVWR). Concepts of operations provide information about 

how each user interacts with these safety systems and their operational conditions. Voluntary 

requirements describe features and functions used to define the safety systems and their 

operational functionality. The information has been developed in collaboration with trucking 

industry stakeholders, including representatives from manufacturers, insurance companies, 

commercial vehicle carriers, drivers and academia. 

The results from this project can be used by motor carriers as system guidelines for voluntary 

adoption of on-board safety systems within their trucking fleets. 

This is a final report developed under FMCSA’s deployment of on-board safety system program. 

It does not supersede an earlier report on the subject. 

 

Notice 

This document is disseminated under the sponsorship of the Department of Transportation in 

the interest of information exchange. The United States Government assumes no liability for its 

contents or use thereof. 

This report does not constitute a standard, specification, or regulation. 

The United States Government does not endorse products or manufacturers. Trade or 

manufacturers' names appear herein only because they are considered essential to the object 

of this document. 
ii 

Acknowledgements 

FMCSA wishes to acknowledge the efforts of those in the government, academia, research 

institutions and industry who contributed their knowledge and expertise to this effort. Those 

individuals include Carl Kirk and Robert Braswell of the Technology and Maintenance Council; 

Marty Fletcher of US Xpress; Jim Kennedy of McKenzie Tanklines; Ron Knipling, PhD of the 

Virginia Tech Transportation Institute; Scott Claffey of Great West Insurance Company; Dave 

Melton of Liberty Mutual Research Institute for Safety; Anne McCartt, PhD of the Insurance 

Institute for Highway Safety; Rick Craig of the Owner Operators Independent Drivers 

Association; Bill Gouse of the American Trucking Associations; Tom Moses of the Spill Center; 

Bob Interbitzen of the National Private Truck Council; Mike Formica and Dean Pomerleau, PhD 

of Assistware; Bill Patrolia of Iteris; Meny Benady of Mobileye; Kevin Romanchok, Jim Szudy, 

and Richard Beyer of Bendix; Alan Korn, Richard Romer, and Mike Lambie of Meritor WABCO; 

Greg Shipman of Delphi; Tom Mattox of Eaton VORAD; Skip Yeakel of Volvo; Charlie Groeller 

of Mack Trucks; Paul Menig of Freightliner; and Dan Murray of the American Transportation 

Research Institute. 
iii 

Technical Report Documentation Page 

1. Report No. 

FMCSA-MCRR-05-005 

2. Government Accession No. 3. Recipient's Catalog No. 

5. Report Date 

July 2005 

4. Title and Subtitle 

Concept of Operations and Voluntary Operational Requirements for Lane Departure 

Warning System (LDWS) On-board Commercial Motor Vehicles 

6. Performing Organization Code 

7. Author(s) 

Amy Houser (FMCSA), John Pierowicz (Calspan Corp.), Dan Fuglewicz (Calspan Corp.) 

8. Performing Organization Report No. 

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

Calspan Corporation 

4455 Genesee Street 

Buffalo, NY 14225 

11. Contract or Grant No. 

DTMC75-03-F-00087 

13. Type of Report and Period Covered 

Technical Report – October 2003-July 2005 

12. Sponsoring Agency Name and Address 

Federal Motor Carrier Safety Administration 

Office of Research and Analysis 

400 Virginia Ave. SW 

Washington, DC 20024 14. Sponsoring Agency Code 

FMCSA 

15. Supplementary Notes 

This program was administered through the Federal Motor Carrier Safety Administration (FMCSA). The FMCSA Program Manager is Mrs. 

Amy Houser. 

16. Abstract 

The Federal Motor Carrier Safety Administration’s (FMCSA’s) safety goal is to reduce the number and severity of large truck fatalities and 

crashes. During the last several years, FMCSA has collaborated with the trucking industry to test and evaluate several on-board safety 

systems for commercial motor vehicles to increase the safety and security of all roadway users. FMCSA is now promoting voluntary adoption 

of these systems within trucking fleets by initiating steps to work closely with the trucking industry to define vendor-independent, voluntary 

requirements. 

The purpose of this document is to relay a better understanding of the functions of on-board safety systems and to provide insight into the 

safety and efficiency benefits of using the systems. The information has been developed in collaboration with expert panels consisting of 

trucking industry stakeholders, including representatives from manufacturers, insurance companies, commercial motor vehicle carriers, 

drivers, and academia. 

This document describes the concept of operations and voluntary requirements for Lane Departure Warning Systems (LDWS) for large trucks 

greater than 10,000 pounds gross vehicle weight rating (GVWR). Concepts of operations provide information about how each user interacts 

with these safety systems and their operational conditions. Voluntary requirements describe features and functions used to define the safety 

systems and their operational functionality. 

17. Key Word 

Commercial Motor Vehicles, Heavy Trucks, Lane Departure, Safety 

Systems, Tractor-Trailers 

18. Distribution Statement 

19. Security Classif. (of this report) 

Unclassified 

20. Security Classif. (of this page) 

Unclassified 

21. No. of Pages 

22 

22. Price 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
iv 

SI* (MODERN METRIC) CONVERSION FACTORS 

APPROXIMATE CONVERSIONS TO SI UNITS APPROXIMATE CONVERSIONS FROM 

Symbol When You Know Multiply By To Find Symbol Symbol When You Know Multiply By 

LENGTH LENGTH 

in inches 25.4 millimeters mm mm millimeters 0.039 incft feet 0.305 meters m m meters 3.28 feeyd yards 0.914 meters m m meters 1.09 Yami miles 1.61 kilometers km km kilometers 0.621 mil

AREA AREA 

in2 square inches 645.2 square millimeters mm2 mm2 square millimeters 0.0016 squft2 square feet 0.093 square meters m2 m2 square meters 10.764 squyd2 square yards 0.836 square meters m2 m2 square meters 1.195 squac acres 0.405 hectares ha ha hectares 2.47 acrmi2 square miles 2.59 square kilometers km2 km2 square kilometers 0.386 squ

VOLUME VOLUME 

fl oz fluid ounces 29.57 milliliters ml ml milliliters 0.034 fluigal gallons 3.785 liters l l liters 0.264 gaft3 cubic feet 0.028 cubic meters m3 m3 cubic meters 35.71 cubyd3 cubic yards 0.765 cubic meters m3 m3 cubic meters 1.307 cub

MASS MASS 

oz ounces 28.35 grams g g grams 0.035 oulb pounds 0.454 kilograms kg kg kilograms 2.202 poT short tons (2000 lbs) 0.907 megagrams Mg Mg megagrams 1.103 sho

TEMPERATURE (exact) TEMPERATURE (exact) 

°F Fahrenheit 5(F-32)/9 Celsius °C °C Celsius 1.8 C + 32 

temperature or (F-32)/1.8 temperature temperature 

ILLUMINATION ILLUMINATION 

fc foot-candles 10.76 lux lx lx lux 0.0929 fl foot-Lamberts 3.426 candela/m2 cd/m2 cd/m2 candela/m2 0.2919 

FORCE and PRESSURE or STRESS FORCE and PRESSURE or ST

lbf pound-force 4.45 newtons N N newtons 0.225 psi pound-force per square inch 6.89 kilopascals kPa kPa kilopascals 0.145 

* SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380.
1 

1. INTRODUCTION 

The Federal Motor Carrier Safety Administration’s (FMCSA’s) safety goal is to reduce the 

number and severity of large truck fatalities and crashes. During the last several years, FMCSA 

has collaborated with the trucking industry to test and evaluate several on-board safety systems 

for commercial motor vehicles to increase the safety and security of all roadway users. FMCSA 

is now promoting voluntary adoption of these systems within trucking fleets by initiating steps to 

work closely with the trucking industry to define vendor-independent, voluntary requirements for 

these systems. 

The purpose of this document is to relay a better understanding of the functions of on-board 

safety systems and to provide insight into the safety and efficiency benefits of using the 

systems. This information was developed in collaboration with expert panels consisting of 

trucking industry stakeholders, including representatives from manufacturers, insurance 

companies, commercial motor vehicle carriers, drivers, and academia. 

This document describes the concept of operations and voluntary requirements for Lane 

Departure Warning Systems (LDWS) for large trucks greater than 10,000 pounds gross vehicle 

weight rating (GVWR). Concepts of operations provide information about how each user 

interacts with these safety systems and their operational conditions. Voluntary requirements 

describe features and functions used to define the safety systems and their operational 

functionality. 

This document discusses vision-based LDWS provided by manufacturers, such as: 

• AssistWare Technology 

• Delphi Electronics and Safety 

• Iteris 

• Mobileye NV 

Appendix A lists the commercial off-the-shelf (COTS) systems that currently exist or will be soon 

released to the market. United States Department of Transportation (USDOT) websites that 

contain further information on governmental research, testing and evaluation of LDWS include: 

www.its.dot.gov/ivi/ivi.htm

www.fmcsa.dot.gov/safetyprogs/research/researchpubs.htm

2. CONCEPT OF OPERATIONS 

Description – Lane Departure Warning Systems 

LDWS are in-vehicle electronic systems that monitor the position of a vehicle within a roadway 

lane and warn a driver if the vehicle deviates or is about to deviate outside the lane. Currently 

available LDWS are forward looking, vision-based systems that use algorithms to interpret video 

images to estimate vehicle state (lateral position, lateral velocity, heading, etc.) and roadway 

alignment (lane width, road curvature, etc.). LDWS warn the driver of a lane departure when 

the vehicle is traveling above a certain speed threshold and the vehicle’s turn signal is not in 

use. In addition, LDWS notify the driver when lane markings are inadequate for detection, or if 

the system malfunctions. 

LDWS do not take any automatic action to avoid a lane departure or to control the vehicle; 

therefore, drivers remain responsible for the safe operation of their vehicles. When the vehicle 

is traveling in close proximity to the center of the lane it is with the systems “no warning zone”, 

the system does not issue any position warnings. As the vehicle deviates from the no warning 
zone the system calculates the time for the vehicle to exit the lane. The LDWS calculates an 

earliest and latest warning line. As shown in Figure 1, the “earliest warning line” is inside the 

lane boundary and the “latest warning line” is outside the lane boundary. The “warning threshold 

placement zone” is the area between the earliest warning lines and the latest warning lines. 

Whenever the vehicle crosses out of the no warning zone into the zone between the earliest 

warning line and latest warning line, the LDWS issues a lane departure warning. Figure 1 

illustrates these warning thresholds. 

Figure 1. LDWS Warning Thresholds and Warning Threshold Placement Zones 

y the fleets as an aftermarket accessory, while 

Crash Prevention 

nt single vehicle roadway departure, lane change/merge, and rollover 

ngle vehicle roadway departure – LDWS issue a warning as the truck crosses the 

d 

03, 

• S issue a warning as the truck crosses center lane 

 dashed 

 

(For illustration only – not to scale.) 

Some of these LDWS may be installed directly b

other LDWS are installed by truck Original Equipment Manufacturers (OEMs) when the vehicles 

are manufactured. As technology advances, new features and components may be added to 

these systems. 

LDWS can help preve

crashes: 

• Si

shoulder lane marking. Without the system, the truck may be driven off the shoulder an

crash into off-road obstacles (e.g., light poles, signs, guardrails, trees, and stopped 

vehicles) or roll over. Data derived from the 2003 General Estimates System (GES)

indicates that 13,000 roadway departure crashes involving large trucks occurred in 20

resulting in 90 fatalities.1

 

Lane change/merge – LDW

markings on multi-lane roadways, including solid lines, double lines, dotted lines,

lines, and raised pavement markers (Bott’s Dots). Without the system, the truck may be 

1

 The General Estimates System is directed by the National Center for Statistics and Analysis, which is a component 

of The Office of Research and Development in NHTSA. Data for GES come from a nationally representative sample 

of police reported motor vehicle crashes of all types, from minor to fatal. The system began operation in 1988, and 

was created to identify traffic safety problem areas, provide a basis for regulatory and consumer initiatives, and form 

the basis for cost and benefit analyses of traffic safety initiatives. The information is used to estimate how many motor 

vehicle crashes of different kinds take place, and what happens when they occur. 

2 
3 

driven into an adjacent lane, resulting in a head-on or sideswipe collision. 

• Rollovers – LDWS may also prevent some crashes that would be categorized as 

r, the 

LDWS 

driver in consistently keeping a vehicle in the lane, thereby reducing lane- 

• r to use turn signals when changing lanes (otherwise, a lane-

• f vehicle position in the lane to maintain a more central 

LDWS warning devices 

Operations and Users 

 drivers, fleet managers, and fleet maintenance personnel interact 

s. At 

perating 

try is 

 

rollover crashes. For example, if the vehicle drifts out of the lane onto the shoulde

truck could roll over if a sudden recovery maneuver is made. A truck may also roll over 

due to any recovery maneuver involving a high lateral velocity (rate of departure), 

requiring a relative large amplitude and/or rapid steering action. 

may also: 

• Assist the 

departure crashes. 

Encourage the drive

departure warning sounds). 

Reinforce driver awareness o

lane position and improve the driver’s attentiveness to the driving task. 

cannot prevent all single vehicle roadway departure crashes. These are 

and do not actively prevent crashes–they warn the driver so he/she can maneuver the truck to 

prevent a crash. For example, crashes involving vehicle loss of control due to slippery roads 

and excessive speed on turns would not be prevented with these systems. Also, the systems 

will not prevent crashes due to intentional lane changes, which involve the driver’s failure to see

another vehicle in the adjacent lane. These crashes can be caused by a driver’s failure to look 

or by an adjacent vehicle being in a blind spot. (Some collision warning systems (CWS) have 

blind spot sensors to help prevent these types of crashes.) Yet, the use of LDWS provides 

immediate warnings to drivers regarding unintentional lane departure events, which may 

improve driving performance over time. 

This section describes how

with LDWS and potential benefits that each stakeholder may realize with these systems. 

The commercial vehicle population is comprised of a wide variety of vehicle types and use

a high level, two types of vehicles are predominant, combination vehicles (tractors-trailers) and 

straight trucks. These two types of vehicles have very different operating characteristics. In 

general, straight trucks tend to be used in a more local setting and provide deliveries of goods 

and services to customers generally within a 50 to 100 mile radius of their base of operations. 

Combination vehicles are more often utilized in regional and long distance applications, and 

account for about 30% of total commercial vehicles, but 65% of the commercial vehicle miles 

traveled. Due to their high mileage exposure and severity of crashes, combination-unit trucks 

have the highest crash cost per vehicle over the operational life of the vehicle.2

 

The trucking industry is actually a broad collection of many industries, each with o

characteristics as diverse as the industries they service. Segmentation of the trucking indus

often based on the size of fleets, the geographic range of its operations and the commodities 

hauled. Usually one characteristic is not adequate to describe a particular segment, but rather

combinations of characteristics are required to best describe operations. For example, there 

may be a trucking firm with a large fleet providing package delivery type service to a relatively 

small geographic area, while there may be a single truck company that provides general freight

2 Wang, J.S.; Knipling, R.R.; and Blincoe, L.J. The Dimensions of Motor Vehicle Crash Risk. Journal of 

Transportation and Statistics. Volume 2, No. 1, pp. 19-43, ISSN 1094-8848, May 1999. 
4 

services to all states in the continental United States. 

The movement of goods by truck is conducted on all types of roads, at all hours of the day, and 

Drivers 

e the primary LDWS users, as described in the following daily operational scenarios: 

r 

S 

imum LDWS tracking speed, 

 When the LDWS cannot track the lane or a system fault occurs, 

ont of 

n 

 types and conditions – A driver may encounter several types of roads and 

red roadway markings include 

r 

undary Markers – If lanes have missing or 

ate 

ings 

in all types of driving conditions. Since unintentional lane departures can occur along any route, 

many fleet types may benefit from using LDWS. Yet, they may be most promising for trucks with 

high mileage accumulated over their operational life or that operate under conditions that may 

present driving challenges such as nighttime, limited visibility due to weather, congestion, or 

roadways of geometry or configuration that can be difficult to negotiate. 

Drivers ar

Normal system startup operation – When the driver turns the ignition switch to start the 

vehicle, the LDWS performs a power-up self-test, and the driver scans the warning indicato

to determine any system malfunctions. If necessary, the driver may alert fleet maintenance 

for corrective action. When the vehicle reaches the minimum LDWS tracking speed on a 

roadway with lane boundary markings, lane tracking begins. The driver can scan the LDW

tracking indicator to verify that lane tracking has commenced. 

Warning/alert situations – When traveling at or above the min

a driver may unintentionally drift out of the lane. Then, the LDWS issues a warning at the 

LDWS warning threshold. 

System fault conditions –

the driver is notified via the lane-tracking indicator. This inability to track lanes may be due 

to a lack of lane markings, poor quality of lane markings, poor visibility, or a dirty/icy 

windshield. Although LDWS cameras typically view the road through a portion of the

windshield swept by the wipers, the driver can manually clean the windshield area in fr

the LDWS camera to see if the LDWS begins to track. Some LDWS may display various 

messages when certain types of faults or other conditions are detected, such as “Calibratio

in Progress”. 

Various road

conditions where these systems perform optimally, but some conditions limited the devices,

especially when lane markings cannot be well-detected. 

Well-Marked Roads – The most commonly encounte

single and double solid lines, dashed and dotted lines, and raised pavement markers

(Bott’s dots) where LDWS should detect lane departures and issue warnings to a drive

traveling over the minimum tracking speed. 

Roads With Missing or Degraded Lane Bo

degraded lane markings, the driver may not receive a warning as the vehicle progresses 

outside of the lane, depending on the particular LDWS used. On roads with only one set 

of markers, the driver should receive a warning when the warning threshold is crossed 

on that side, even if the system cannot detect the lane boundary on the other side. 

Delivery Points, Arterials, and Collectors – Currently available LDWS will not oper

at delivery points and roads where the truck travels at speeds below the minimum LDWS 

tracking speed. Currently available LDWS are geared primarily for highway driving and 

will not function at lower speeds associated with some local roads. As a result, the 

LDWS would notify drivers that the system is operational, but it is not providing warn

under these conditions. 
5 

Wet Roads – Due to reflections on wet road surfaces, LDWS may occasionally be 

unable to detect lane markings; however, the lane-tracking indicator will show that the 

system is not providing warnings under these conditions. 

Mud-/Ice-/Snow-Covered Roads – When lane markings are not visible on roads 

covered by mud, ice, or snow, the lane tracking indicator will show that the system is 

inactive. LDWS may be beneficial in low visibility conditions (e.g., rain, fog, and falling 

snow) when lane markings are present. 

Fleet Management 

Fleet managers are responsible for all administrative, financial, and operational aspects of the 

fleet. Safety officers focus on the fleet’s operational safety issues and examine the safety 

aspects of the fleet’s vehicles in accordance with USDOT safety regulations. They also work 

with drivers to provide safety and operational training, verify that drivers are complying with 

safety regulations, and examine how well drivers operate their vehicles (e.g., logging accidents, 

traffic infractions, etc.). 

These personnel examine various types of available safety equipment, evaluate the equipment, 

justify the purchase of all equipment, determine the overall effectiveness of this equipment, and 

calculate the return on investment (ROI) for their fleet. They work with the maintenance 

department and drivers to explain LDWS benefits. Fleet managers may obtain operational data 

(e.g., number of lane departures) from LDWS via the in-vehicle network, and analyze the data to 

determine any systemic problems with their fleet operations (e.g., disproportionate number of 

lane departures with certain drivers, high number of lane departures on certain routes) and to 

use for driver training. Research has indicated that the monitoring of driver behavior may have 

a positive effect on driver and fleet safety.3 In the Fatigue Management Technology Pilot Test, 

drivers’ opinions were positive towards the use of the LDWS deployed in this test, and the 

results of this specific test showed that drivers prefer vehicle monitoring versus driver monitoring 

as a means of driver feedback.4

Maintenance Management and Installation 

Maintenance managers and service technicians are responsible for the proper functioning of all 

equipment installed on the fleet’s vehicles and for installing and maintaining LDWS on the fleet. 

They support fleet management by collecting operational data on the reliability of LDWS and 

how well LDWS suppliers work with the fleet to resolve any problems if LDWS are not supplied 

directly by the truck OEMs. 

LDWS have different installation requirements for each vehicle type. Depending on the system, 

LDWS may be installed by a truck OEM or as an aftermarket accessory by the fleet or other 

service personnel. 

When the currently available vision based LDWS is installed by a truck OEM, the LDWS camera 

location and mounting bracket attachment method are similar for each vehicle type. The OEM 

provides dedicated wiring harnesses for the connection between the LDWS and the vehicle. If 

 3 Knipling, R.R.; Boyle, L.N.; Hickman, J.S.; York, J.S.; Daecher, C., Olson, E.C.B., and Prailey, T.D. Synthesis 

Report # 4: Individual Differences and the High-Risk Commercial Driver. Project Final Report, Transportation 

Research Board Commercial Truck and Bus Synthesis Program. ISSN 1544-6808, ISSN 0-309-08810-0, 

available at http://trb.org/news/blurb_browse.asp?id=11, 2004.

4

 Dinges, David F.; Maislin, Greg; Brewster, Rebecca; Krueger, Gerald P.; and Carroll, Robert, J. “Pilot Test of 

Fatigue Management Technologies”, Paper No. 05-1234, TRB 2005 Annual Meeting. 
6 

necessary, the OEM enters system settings, such as the height of the camera from the ground, 

and the position of camera relative to the middle of the windshield, to configure the system for 

proper operation. 

When the currently available vision based LDWS is installed as an aftermarket accessory, the 

LDWS camera must be properly oriented, pointing directly toward the middle of the lane and 

angled slightly downward, as described in the user’s manual. Then, key parameters are entered 

into the system, including the height of the camera from the ground and the position of the 

camera relative to the middle of the vehicle. 

3. VOLUNTARY REQUIREMENTS 

The voluntary requirements included in the following sections define fundamental LDWS 

features and the ability of LDWS to withstand the electrical and environmental extremes 

commonly found on commercial vehicles. 

The types of voluntary requirements for LDWS include: 

1. Functional Requirements 

2. Data Requirements 

3. Hardware and Software Requirements 

4. Driver Vehicle Interface (DVI) Requirements 

5. Maintenance and Support Requirements 

LDWS manufacturers may include additional functions and features that may be useful beyond 

minimum LDWS functionality; the operational features that fall into this category are labeled with 

the term “OPTIONAL”. However, in all cases, LDWS must comply with all existing FMCSA 

Safety Regulations. The requirement numbering system designates optional features with a “T” 

and system defining requirements with an “R”. 

3.1 Functional Requirements 

Functional requirements refer to the basic functionality and operation of LDWS. 

R1-1 LDWS should perform a self-test that checks all major system sensors and 

components, operate within 30 seconds of starting the vehicle, and relay the 

results of the self-test to the driver indicating whether the system is 

operational. 

R1-2 LDWS should detect vehicle position relative to following types of visible lane 

boundaries: 

• Solid and dashed painted lines 

• Single and double painted lines 

• Yellow and white painted lines 

• Raised pavement markers (Bott’s dots) 

• Lines with and without reflectors/reflective material 

R1-3 LDWS should issue warnings, detect vehicle position relative to visible lane 

boundaries, and track lane boundaries when the vehicle is traveling at or 

above a speed of 60 kilometers per hour (kph) (37 miles per hour (mph)). 

R1-4 LDWS should issue warnings, detect vehicle position relative to visible lane 

boundaries, and track lane boundaries where lane markings are clearly 

visible in daylight (sunny/cloudy), nighttime (with and without streetlight 
7 

illumination), and twilight (sunrise/sunset) lighting conditions. 

R1-5 ehicle departs 

 

R1-6

LDWS should use warning thresholds to determine when the v

a lane, or is about to leave the lane. At least one warning threshold should be 

established for each side of the lane and should be optimized for the specific 

type of commercial motor vehicle, such that nuisance alarms are minimized 

and threshold warnings are given in time for the driver to make a correction. 

 of 

R1-7

LDWS should be able to track lane boundaries and issue warnings within 

±0.1 meter (±4 inches) from the warning thresholds when the vehicle’s rate

lane departure is < 0.8 m/s (2.6 ft./s).5

LDWS should be able to track the lane boundary that the vehicle is heading 

towards 95% of the time on dry straight roads when lane boundary markings

of the types listed in R1-2 are present. 

R1-8 LDWS should be able to issue lane departure warnings 95% of the time, for 

both left and right lane departures, on dry straight roads when lane boundary

markings of the types listed in R1-2 are present. 

R1-9 LDWS should issue lane departure warnings on straight roadways as 

described in R1-8. LDWS should also issue warnings when at least on

the roadway curvature test conditions listed in Table 1 is encountered.

e of 

Table 1 

LDWS Warning Curv ay Test Conditions 

6

 

ed Roadw

Condition Road Curvature 

Radius Operating Speed 

1 (metric units) ≥ 250 m < 72 kph, ≥ 61 kph 

1 (English units) ≥ 820 feet < 45 mph, ≥ 38 mph 

2 (metric units) ≥ 500 m ≥ 72 kph 

2 (English units) ≥ 1640 feet ≥ 45 mph 

R1-10 LDWS should not issue warnings for lane departures when the driver uses 

R1-11

the vehicle’s turn signal in the intended direction of the lane change. 

 LDWS should function properly when the windshield wipers are operating. 

T1-1 OPTIONAL – LDWS may issue directional warnings to alert the driver to 

which side of the lane the vehicle is drifting. A directional warning may be

audible, such as rumble strip sounds in left or right in-cab speakers, or tactile. 

T1-2 OPTIONAL – When driving along a curve, LDWS may move the warning 

threshold farther out, allowing “curve cutting” behavior. However, the warn

threshold should not be placed beyond the latest warning line. Curve cutting 

is the act of driving to the inside of a curved section of roadway or taking a 

small shortcut across the curve. 

ing 

 

5 International Standard: ISO/CD17361 5.2. Intelligent Transport Systems - Lane Departure Warning Systems - 

Performance Requirements and Test Procedures. June 23, 2003. 

6

 International Standard: ISO/CD17361 5.2. Intelligent Transport Systems - Lane Departure Warning Systems - 

Performance Requirements and Test Procedures. June 23, 2003. 
8 

T1-3 OPTIONAL – LDWS may provide a warning based on the analysis of Time to 

Lane Crossing (TLC). In this mode, the warning is issued prior to the actual 

crossing of the warning line. Lateral vehicle motion may be analyzed to 

calculate the TLC value. 

T1-4 OPTIONAL – LDWS may provide a differential warning based on the type of 

lane boundary (e.g., solid or dashed). The difference may be observed in the 

volume or length of the alert. 

T1-5 OPTIONAL – LDWS may provide a warning upon crossing a road edge in 

absence of lane markings, or suppress it. 

T1-7 OPTIONAL – LDWS may report system fault conditions on construction 

areas where multiple or conflicting lane boundaries exist. 

T1-8 OPTIONAL – LDWS may issue warnings when turn signals are left on for 

more than a pre-specified threshold period. 

3.2 Data Requirements 

This section defines the format of data generated by or can be obtained directly in real-time 

from LDWS. Two Society of Automotive Engineers (SAE) standards specify in-vehicle data 

communication in heavy trucks: 

• SAE J1587, “Electronic Data Interchange between Microcomputer Systems in HeavyDuty Vehicle Applications” (message definition for the J1708 data bus), or 

• SAE J1939-71, “Recommended Practice for Control and Communications Network for 

On-Highway Equipment – Vehicle Application Layer” 

The data may be obtained via the On-Board Diagnostic (OBD) connector from one of the invehicle data networks, J1708 or J1939, as defined by their respective Society of Automotive 

Engineers (SAE) standards. 

T2-1 OPTIONAL – LDWS may have the capability to store operational data for 

providing driving feedback to drivers. 

3.3 Hardware and Software Requirements 

Hardware and software requirements deal directly with the detailed functionality of the 

hardware, environmental and electrical concerns, mounting/installation issues, and software 

design. Figure 2 illustrates the major functional components and interfaces of LDWS, as 

described in the following section. It shows the inter-relationship of the LDWS components. 

The electronic control unit (ECU) accepts data from the lane boundary sensor. Through the 

vehicle network (J1708 or J1939), the ECU monitors the turn signal status and engine power. 

The output of the system is a status indicator and, when necessary, a warning, which appear on 

the driver-vehicle interface. 
Figure 2 

LDWS Major Functional Components 

Typical System Hardware 

This section describes the functionality of the primary physical components of LDWS. They refer 

to the functional blocks shown in Figure 2. 

R3-1 Lane Boundary Sensor – A lane boundary sensor should detect vehicle 

position relative to visible lane boundaries and track lane boundaries. If the 

detector is a vision-based system, the image of lane boundaries may be 

black and white or color and may be transferred in either digital or video 

format. 

R3-2 Electronic Control Unit (ECU) – The LDWS ECU should process data from 

lane boundary sensors to establish whether the vehicle is within the no 

warning zone or has crossed a warning threshold. The LDWS ECU should 

detect when the vehicle drifts toward an unintended (no active turn signal) 

lane change and automatically emit a warning for the driver to make a 

correction. 

R3-3 Driver Vehicle Interface – LDWS should provide a Driver Vehicle Interface 

(DVI) for the driver to interact with the system. The LDWS DVI consists of 

controls, indicator lights, and audio sources used by the driver for LDWS 

operation. The LDWS DVI may include an alphanumeric or graphical display. 

See Section 3.4 for additional DVI requirements. 

R3-4 Turn Signal Status – LDWS should monitor the turn signal’s status and 

issue lane departure warnings only when the driver does not use the 

vehicle’s turn signal in the intended direction of the lane change. 

R3-5 Vehicle Power – Vehicle power should provide power to LDWS. 

R3-6 Driver Warning – LDWS should provide a warning to the driver when the 

vehicle drifts out of the lane or is about to leave the lane. This warning can be 

audible, visual, or tactile.

R3-7 Visual Status Indication – LDWS should self-diagnose a failure and provide 

a visual indication to alert the driver of the system status, which includes 

operational/non-operational, tracking/not-tracking, and system fault 

conditions. 

T3-1 OPTIONAL – Vehicle Network – LDWS may use the in-vehicle data network 

9 
10 

(SAE J1708 or J1939) for data communication to data recording or diagnostic 

devices. 

Environmental Requirements 

The SAE has developed a comprehensive standard that describes various aspects of the heavy 

truck environment in its J1455 standard, which includes procedures to verify system 

compliance. 

R3-8 LDWS should meet the environmental requirements as stated in the most 

recent version of the following SAE standard: 

SAE Standard J1455, “Joint SAE/ Technology and Maintenance Council 

(TMC) Recommended Environmental Practices for Electronic Equipment 

Design (Heavy-Duty Trucks)”. The following environmental aspects are 

covered by the standard: 

• Altitude 

• Fungus 

• Mechanical Shock 

• Mechanical Vibration 

• Relative Humidity 

• Temperature 

• Salt Spray Atmosphere 

• Immersion and Splash 

• Steam Cleaning and Pressure Washing 

• Dust, Sand, and Gravel Bombardment 

Electrical Requirements 

In a truck’s electrical power distribution system, the system voltage may vary, electrical noise 

may be generated by the alternator, and various types of transients may momentarily place over 

100 volts direct current (VDC) on the electrical distribution system’s wiring. In addition, 

electrostatic discharge into the system may occur from a buildup of static electricity. Since 

LDWS may be connected to the electrical power distribution system, they should function 

normally throughout all of these perturbations without damage. 

R3-9 LDWS should meet the electrical requirements as stated in most recent 

version of the following SAE standards: 

SAE Standard J1455, “Joint SAE/TMC Recommended Environmental 

Practices for Electronic Equipment Design (Heavy-Duty Trucks)”. 

SAE Standard J1113, “Electromagnetic Compatibility Measurement 

Procedures and Limits for Vehicle Components (Except Aircraft) (60 Hz to 

18 GHz)”. 

The following environmental aspects are covered by the standards: 

• Steady State Electrical Characteristics 

• Transient Electrical Characteristics 

• Electromagnetic Susceptibility 

• Electromagnetic Emission 

R3-10 LDWS data should not be destroyed nor corrupted during a power surge. 

Mounting and Installation Requirements 

Mounting and installation requirements include all aspects related to the installation of LDWS 

hardware onto the vehicle. There are no specific requirements pertaining to system size or 
11 

weight. 

R3-11 If sensors, such as vision-based LDWS cameras are mounted in the swept 

area of the windshield, they should be small enough to preclude obstructing a 

driver’s vision. 

R3-12 LDWS sensor mounting should isolate sensors, such as vision-based LDWS 

cameras, from mounting surface vibrations. 

R3-13 All LDWS cables, connectors, and components should be rated for 

automotive duty as defined by the SAE and be appropriate for their 

operational environment (e.g., LDWS components mounted on the exterior of 

the vehicle should be rated for exterior duty). 

R3-14 Major LDWS components, other than cabling or small mounting components, 

should be marked with the manufacturer’s identification. 

Software Requirements 

Software requirements refer to the embedded software that runs in LDWS and controls all 

LDWS functionality. The microcontroller or microprocessor continuously runs LDWS software 

when the system is active. 

T3-2 OPTIONAL – LDWS may include software for downloading ASCII data files 

that can be easily read into a statistical, database, or spreadsheet software 

package. 

T3-3 OPTIONAL – The embedded software of LDWS may be field upgradeable 

via the in-vehicle network connection (i.e., J1587 or J1939) or other common 

data interface (e.g., RS-232 or USB). 

3.4 Driver Vehicle Interface Requirements 

These requirements define LDWS interface with the driver, which includes indicators, displays, 

and warning methods. The National Highway Traffic Safety Administration (NHTSA) Federal 

Motor Vehicle Safety Standard 101 (FMVSS 101) should be used as a guide for LDWS 

indicators. 

R4-1 LDWS should issue an audible or tactile warning when the vehicle crosses 

the warning threshold. 

R4-2 LDWS should include a visual indicator to indicate when the system is not 

tracking the vehicle’s position in the lane. This status may be indicated by an 

instrument panel warning light or an indicator that is integral to LDWS. 

R4-3 LDWS should use a visual indicator to indicate that the system is operational 

and ready to function. This status may be indicated by an instrument panel 

warning light or an indicator that is integral to LDWS.

R4-4 LDWS should use a visual or audible indicator to indicate a system failure or 

malfunction. This status may be indicated by an instrument panel warning 

light or an indicator that is integral to LDWS.

R4-5 LDWS indicators should be clearly discernable in direct sunlight and at night. 

T4-1 OPTIONAL – LDWS may graphically indicate on a user interface display the 

vehicle’s position relative to both lane boundaries, and to which side of the 

lane a departure occurs. 
12 

T4-2 OPTIONAL – LDWS may graphically indicate on a user interface display 

when lane tracking is not being performed, and may indicate which side is or 

is not tracking. 

T4-3 OPTIONAL – LDWS may provide a directional or non-directional tactile 

warning (e.g., rumble seat) to indicate a lane departure in the left or right 

direction. 

T4-4 OPTIONAL – LDWS may allow the volume of the audible warnings to be 

adjusted, but not below a minimum sound level of 65 dBA.7

T4-5 OPTIONAL – LDWS may graphically indicate on a user interface display how 

well the vehicle is centered in the lane on a time-averaged basis.

T4-6 OPTIONAL – LDWS may provide operational or diagnostic messages or 

codes such as “System Operational”, “Lane Tracking Active”, or “Clean 

Windshield” on an alphanumeric display to alert the driver of specific faults, 

conditions, or concerns. 

3.5 Maintenance and Support Requirements 

Maintenance and support requirements include functionality/features that should be provided to 

ensure LDWS will be operated correctly and properly maintained. 

R5-1 The only driver maintenance LDWS should require is maintaining a clean 

windshield and camera lens for vision-based LDWS.

R5-2 LDWS should automatically maintain calibration on a particular vehicle to 

compensate for normal or expected changes in vehicle loading (e.g., 

full/empty gas tank, truck with/without trailers, with/without cargo, and one or 

more passengers). 

R5-3 An operator’s manual or other document should supply a user procedure to 

verify that LDWS are calibrated and functional. 

R5-4 Users should be provided with a manual and training for LDWS. All 

application software programs should include installation instructions and 

user manuals. 

R5-5 At a minimum, the user’s manual should include information on the minimum 

vehicle speed at which LDWS operate, the types of markings LDWS can 

track, and the types of indicators used to inform drivers LDWS are functioning 

properly and tracking the lane. 

T5-1 OPTIONAL – Video, audio, or computer-based training material may be 

provided for fleet management and/or drivers. 

T5-2 OPTIONAL - LDWS may be transferable from one vehicle to another. Forced 

recalibration and/or resetting of system parameters may be necessary when 

LDWS are transferred between vehicles. 

 

7 For reference: 90 dBA = heavy truck at 10m, 80 dBA = curbside of busy street, 70 dBA = car interior, 

60 dBA = normal conversation at 1m (3.28 ft.), and 50 dBA = office noise. 
13 

4. ACRONYMS 

Acronym Definition 

ASCII American Standard Code for Information Exchange 

COTS Commercial Off-The-Shelf 

CWS Collision Warning Systems 

DVI Driver-Vehicle Interface 

ECU Electronic Control Unit 

FMCSA Federal Motor Carrier Safety Administration 

FMVSS Federal Motor Vehicle Safety Standard 

FOT Field Operational Test 

GES General Estimates System 

GVWR Gross Vehicle Weight Rating 

HMI Human Machine Interface 

ISO International Standards Organization 

kph Kilometers per Hour 

LDTS Lane Detection and Tracking Subsystem 

LDW Lane Departure Warning 

LDWS Lane Departure Warning System(s) 

L/SH Local/Short-Haul 

LH Long-Haul 

LED Light Emitting Diode 

mph Miles per Hour 

NHTSA National Highway Traffic Safety Administration 

OBD On-Board Diagnostic 

OEM Original Equipment Manufacturer 

ROI Return on Investment 

SAE Society of Automotive Engineers 

TLC Time to Lane Crossing 

TMC Technology and Maintenance Council 

USB Universal Serial Bus 

USDOT United States Department of Transportation 

VDC Volts Direct Current 
14 

5. REFERENCES 

Dinges, David F.; Maislin, Greg; Brewster, Rebecca; Krueger, Gerald P.; and Carroll, 

Robert, J. “Pilot Test of Fatigue Management Technologies”, Paper No. 05-1234, TRB 2005 

Annual Meeting. 

Draft International Standards Organization (ISO) Standard ISO/CD17361, “Intelligent 

Transport Systems, Lane Departure Warning Systems – Performance Requirements and 

Test Procedures”, June 23, 2003. 

Insurance Institute for Highway Safety, “Request for Comments on Proposal for Pilot 

Program, Younger Commercial Driver Pilot Training Program”, Docket No. FMCSA-2000-

8410, May 21, 2001. 

SAE Standard J1113, “Electromagnetic Compatibility Measurement Procedures and Limits 

for Vehicle Components (Except Aircraft) (60 Hz to 18 GHz)”, July 1995. 

SAE Standard J1455, “Joint SAE/TMC Recommended Environmental Practices for 

Electronic Equipment Design (Heavy-Duty Trucks)”, August 1994. 

SAE Standard J1587, “Electronic Data Interchange between Microcomputer Systems in 

Heavy-Duty Vehicle Applications”, February 2002. 

SAE Standard J1708, “Serial Data Communications between Microcomputer Systems”, 

October 1993. 

SAE Standard J1939-71, “Recommended Practice for Control and Communications Network 

for On-Highway Equipment – Vehicle Application Layer”, September 2002. 

Wang, J.S.; Knipling, R.R.; and Blincoe, L.J. The Dimensions of Motor Vehicle Crash Risk. 

Journal of Transportation and Statistics. Volume 2, No. 1, pp. 19-43, ISSN 1094-8848, 

May 1999. 

Wierwille, W.W.; Lewin, M.G.; and Fairbanks, R.J. III. Final Report: Research on VehicleBased Driver Status/Performance Monitoring; Part I. Vehicle Analysis and Simulation 

Laboratory, Virginia Polytechnic Institute and State University, Publication No. DOT HS 808 

638, September 1996. 

Wierwille, W.W.; Lewin, M.G.; and Fairbanks, R.J. III. Final Report: Research on VehicleBased Driver Status/Performance Monitoring; Part II. Vehicle Analysis and Simulation 

Laboratory, Virginia Polytechnic Institute and State University, Publication No. DOT HS 808 

638, September 1996. 

Wierwille, W.W.; Lewin, M.G.; and Fairbanks, R.J. III. Final Report: Research on VehicleBased Driver Status/Performance Monitoring; Part III. Vehicle Analysis and Simulation 

Laboratory, Virginia Polytechnic Institute and State University, Publication No. DOT HS 808 

638, September 1996. 
15 

A. APPENDIX A – COMMERCIAL OFF-THE-SHELF LDWS 

The following Commercial Off-the-Shelf (COTS) LDWS are currently available: 

AssistWare Technology (www.assistware.com) – The “SafeTRAC Drowsy Driver Warning 

System” includes a digital camera and an image processing/user display unit. The user 

display contains an alphanumeric/graphical display to indicate vehicle position in the lane 

and to provide an alertness measure that indicates a driver’s consistency in maintaining a 

vehicle’s position within the lane. The system includes an audible lane departure warning 

and ability to control vibrating (haptic) seats as an auxiliary warning device. The system’s 

warning thresholds and warning volume are adjustable. The system detects visual lane 

markings and can estimate some lane boundaries when visual lane markings are not 

present. The system is available as either a factory-installed or an aftermarket system. 

Delphi Electronics and Safety (www.delphi.com) – The “Delphi Lane Departure Warning 

System” can be installed by Original Equipment Manufacturers (OEMs) or aftermarket 

consumers on passenger cars and large commercial vehicles. The Delphi LDWS includes a 

forward-looking camera, image-processing unit, and human machine interface (HMI), such 

as a graphical driver display. Functionally, the system is a combination of three distinct 

parts. The Lane Detection and Tracking Subsystem (LDTS) detects and tracks the lane 

boundaries. Results of this process are passed to the Warning Subsystem, which 

determines if and when a lane departure warning should be issued. Warning requests are 

sent to the HMI Subsystem, which provides the alerts to the driver. The system has a visual 

directional warning and an audible alert signal whose particular sound can be customized 

for OEMs. The system also has the ability to control tactile warnings. The warning 

threshold can be calibrated (i.e., customized) to satisfy a fleet company's requirement. The 

system is now in development. It is expected to be released Q3 2005. 

Iteris (www.iteris.com) – The “Auto VueTM Lane Guidance, Lane Departure Warning 

System” includes a digital camera and an image processing unit. A green light emitting 

diode (LED) indicates system status; a yellow LED indicates whether the system is tracking 

the lane. The system has a directional audible lane departure warning and the ability to 

control haptic seats as an auxiliary warning device. The warning thresholds are not 

adjustable. The system, which is available for light vehicles and heavy trucks, is typically 

installed by a vehicle manufacturer and calibrated at the factory for each vehicle model, but 

can also be installed as an aftermarket system. 

Mobileye (www.mobileye.com) – The “Mobileye Lane Departure Warning (LDW) System” 

includes a camera and a processing unit mounted to the center of the windshield and a cell 

phone-sized alphanumeric/graphic driver display on the dashboard. Two in-cab speakers, 

one on either side of the vehicle, provide audible directional warnings. The warning volume 

is adjustable. The system detects visual lane markings and estimates lane boundaries 

when visual lane markings are not present. The system predicts the time and provides an 

early warning of lane crossing by measuring lateral vehicle motion. The system can be 

installed as an aftermarket system, stand-alone, or as an additional feature with headway 

monitoring. 
16 

Summary of COTS System Features 

Table A-1 provides comparative information relative to the features of each of the COTS 

systems described in this appendix. Each manufacturer provided this information. 

Table A-1 

Summary of COTS LDWS Features 

Feature AssistWare Delphi Iteris Mobileye 

Detects lane boundaries based on lane markers Yes Yes Yes Yes 

Estimates boundaries when markers not present/visible Yes Limited No Yes 

Audible lane departure warning Yes Yes Yes Yes 

Supports tactile (vibratory) lane departure warnings Yes Yes Yes No 

Lane tracking indicator Yes Yes Yes Yes 

System status indicator Yes Yes Yes Yes 

Aftermarket installation by fleets possible Yes Yes Yes Yes 

Currently sold as aftermarket product Yes No Yes Yes 

Currently installed by OEMs Yes No Yes No 

Fleet adjustable warning thresholds Yes Yes No Yes 

Factory adjustable warning thresholds Yes Yes Yes Yes 

Alphanumeric/graphical display Yes Yes No Yes 

Displayed driver alertness measure Yes No No No 

Directional warnings No Visual Audible Audible & 

Visual 

Data link protocol RS-232 

or J-1587 J-1587 J-1939 Ethernet 

or USB 2.0
Report No. FMCSA-MCRR-05-005 

For more information on the Federal 

Motor Carrier Safety Administration and 

the Office of Research and Analysis, 

check out our website at www.fmcsa.dot.gov