Volvo Intelligent Vehicle Initiative Field Operational Test

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Volvo Intelligent Vehicle Initiative Field Operational Test
General information
Type: Field operational test
Tested system/service: Autonomous Systems
Countries: USA 1000 test users
? partners ? vehicles
Active from 09/1999 to 2005
Summary paper (PDF)
Matthew J. Lehmer
United States Department of Transportation
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Under the United States Department of Transportation (USDOT) Intelligent Vehicle Initiative (IVI), Volvo Trucks North America, Inc. tested three systems for commercial vehicles: Collision Warning System (CWS), Adaptive Cruise Control (ACC), Advanced Braking System (AdvBS).

The systems are designed to assist commercial vehicle drivers in reducing the occurrence and severity of rear-end crashes as well as lane change/merge crashes.

For purposes of conducting this FOT, the Volvo Partnership included US Xpress Enterprises, Inc. (affiliated with US Xpress Leasing, Inc.), the fleet operator; the USDOT; and several technology and supplier participants, including Eaton VORAD, Eaton Bosch, and Aberdeen Test Center.

Data were collected during 3 years from an onboard data acquisition system (DAS) on each tractor and were combined with historical crash data and data from other sources.

Key milestones of the project

  • The start date for the Baseline and Control vehicles was approximately January 1, 2001.
  • The Test vehicles were entered into service beginning in March 2001, with a data collection start date of approximately July 1, 2001.
  • Data collection was phased out vehicle by vehicle as the instrumentation was removed from the vehicles beginning in the second quarter of 2003.

Details of Field Operational Test

Start date and duration of FOT execution

Start: January 2001

Duration : 3 years

Geographical Coverage

Whole United States

Link with other related Field Operational Tests

In 1999, USDOT entered into cooperative agreements with four partnerships to conduct Generation 0 Field Operational Tests (FOTs) of advanced intelligent vehicle safety systems (IVSS). The 4 partnerships are:

  • Minnesota DOT tested technologies designed to provide operators of snowplows, ambulances, and patrol cars a means to maintain desired lane position and avoid collisions with obstacles during periods of low visibility. Key among these technologies are vision enhancement, lateral guidance, and collision warning systems.
  • Volvo Trucks North America, Inc., in partnership with U.S. Xpress, tested a forward collision warning system, a blind spot warning system (not under evaluation), an adaptive cruise control, and an advanced electronic braking system for commercial vehicles
  • Mack Trucks, Inc., in partnership with McKenzie Tank Lines, will test a trucker safety advisory system and a lane departure warning system for commercial vehicles
  • Freightliner Corporation, in partnership with Praxair, tested a roll stability advisor and a roll stability control to assist commercial vehicle drivers in avoiding rollover crashes.


The objectives of the FOT were:

  • Evaluate the performance of the safety systems as operated in a real-world environment
  • Accelerate the deployment of the systems
  • Help forge strategic partnerships in the transportation industry as a model for public/private cooperation for the development and deployment of advanced transportation safety technologies
  • Assess the state-of-the-art in safety benefits analysis for vehicle-integrated advanced safety systems.


For commercial vehicles, the CWS alone and the bundled system of the CWS, ACC, and AdvBS were found to provide a significant safety benefit during periods of prolonged highway speed driving (>24.6 m/s, or >55.0 mi/h) and during near-crash events that happen at a high speed. Specifically, when more than 75 percent of the time spent was spent at highways speeds, there is a statistically significant reduction in the exposure to conflicts for trucks equipped with the CWS, demonstrating that the CWS is more effective at preventing conflicts when used at highway speeds than at lower speeds. The results for the bundled system compared to no safety system indicated that there is a significant reduction in the exposure to conflicts for trucks with the bundled system as compared to trucks with no safety system when more than 47 percent of the time is spent at highway speeds in a three hour period, independent of cruise control usage.

For large trucks, from an economic benefit-cost perspective, the deployment of the bundled system on the fleet of all large trucks cannot be justified at a societal level under any scenario considered. This is partially driven by the high cost of the AdvBS. Even under the most optimistic future cost assumptions, the economic benefits from deployment of the CWS alone on all large trucks (without the expense of the AdvBS) would be only approximately equal to the cost of deployment.

For tractor-trailers, it appears that in a competitive market, the deployment of CWS on all tractor-trailers, on the other hand, can produce safety benefits that exceed the cost of deployment. Deployment of ACC might produce additional safety benefits at a relatively small cost. However, the relative benefits and costs of deploying AdvBS require additional study. The drivers appear convinced that these braking systems improve driving safety; however, it was not possible to fully document these benefits in this FOT.

Lessons learned

Main events


Summary, type of funding and budget

3.3 Mio $ funded under the United States Department of Transportation (USDOT) Intelligent Vehicle Initiative (IVI)

Cooperation partners and contact persons

  • Public Authorities: United States Department of Transportation (USDOT), National Highway Traffic Safety Administration (NHTSA), Aberdeen Test Center
  • Industry
    • Vehicle Manufacturer: Volvo Trucks North America
    • Supplier: Eaton VORAD, Eaton Bosch
  • Users:
  • Universities:
  • Research Institutes:
  • Others (specify): US Xpress Leasing, Inc. (fleet operator)

Applications and equipment

Applications tested

The safety systems in the FOT included a rear-end collision warning system (CWS), adaptive cruise control (ACC), and an electronically controlled brake system (ECBS), which included air disc brakes (ADB).


100 Volvo VN770 tractors (long-haul trucks)

Leased vehicles by US Xpress for their normal service

Equipment carried by test users



Test equipment

In order to collect information onboard the vehicles, all 100 tractors were equipped with a data acquisition system (DAS), specifically designed by ATC for the purpose of collecting field data in the Volvo IVI FOT.

Video recording equipment was also present on the tractors. Video was recorded to correlate critical events and their resolution with the vehicle data collected by the DAS.


Pre-simulation / Piloting of the FOT


Method for the baseline

  • 50 “Test” vehicles: equipped with the three safety technologies: CWS, ACC and AdvBS.
  • 30 “Control” vehicles: equipped with CWS.
  • 20 “Baseline” vehicles: equipped with a disabled CWS for the first 18 months of the FOT, and then with an enabled CWS for the remaining time of the FOT. When the CWS was disabled, data were collected, but the driver display was not active and alerts were not communicated to the drivers.

Techniques for measurement and data collection

The DAS was designed to transfer data stored onboard to a remote location autonomously by wireless means using cellular communications, or manually by replacement of a PCMCIA (Personal Computer Memory Card International Association) flash memory card.

Objective (logged data…):

Collecting and storing data continuously at a sufficient and appropriate data collection rate for each mile driven by the vehicle could not be reasonably implemented onboard the tractors, in part because of the cost of transferring large amounts of data with wireless cellular communications. As such, to ensure that the total amount of data collected was manageable, data were stored in two different formats onboard the computer, depending on the need and end use of the data element: histogram format and time history format.

Histograms represent a driving period during which certain variables are monitored continuously and during which an event could have occurred triggering additional data collection. Examples of data elements stored in a histogram format are “following interval” and “cruise control use”. These data elements provide generic information on driving behaviors that can be compared between groups of drivers exposed to different technologies and can be used by the Evaluation Team to address hypotheses.

In situations where more detailed information was needed to evaluate the technology and/or the driver’s response to the technology, vehicle data were stored in a detailed, continuous “time history” data file format, rather than in the summarized histogram format. The creation of time history data files was prompted by events that were recognized by the Evaluation Team as representative of situations leading to rear-end crashes. As such, a total of eleven unique triggers were pre-defined to capture events when a lead vehicle may be too close based on:

  • Conditions leading to VORAD® alarms
  • Strong truck deceleration
  • Rapid truck lane change.

The “time history” data files consisted of up to 17 measurement channels recorded continuously at 6 Hz.

Subjective (questionnaires, focus groups…):

The method for collecting data was to conduct telephone interviews with drivers using a survey questionnaire to guide the interviews. The answers to the survey questions were entered into a computer using a Computer-Aided Telephone Interview (CATI) system. This allowed automated checks for the validity of responses and transfer into a database for further analysis

Recruitment goals and methods

For the most part, US Xpress assigned drivers to trucks according to their normal operational needs and procedures. However, special procedures were established for assigning drivers to the Baseline vehicles. CWS had been in use for several years at US Xpress, so most drivers had experience with the system prior to the start of the FOT. Because CWS was expected to change driving behavior on a long-term basis, the data collected from Baseline units driven by existing US Xpress drivers would not have been representative of drivers with no prior experience.

Therefore, to the extent possible, new hires, with no previous experience with the CWS at US Xpress, were assigned to the Baseline vehicles. Since the US Xpress driver turnover rate is greater than 100 percent per year, the total number of drivers involved in the FOT exceeded 1,000.

Methods for the liaison with the drivers during the FOT execution

Driver background information was managed by US Xpress’ recruitment department. Throughout the FOT, US Xpress sent Battelle via email the driver background information in a MS Excel or ASCII file.

Drivers recorded their daily activities (driving, on duty, sleeper berth, or off duty) on a paper log sent monthly to the fleet operator.

Methods for data analysis, evaluation, synthesis and conclusions

The USDOT contracted with Battelle to perform an independent evaluation of the FOT. Specifically, the goals of the independent evaluation were:

  • Estimate safety benefits
  • Perform a benefit-cost analysis
  • Assess driver acceptance of the new technology.

Battelle performed an independent evaluation of the FOT. The safety benefits of the advanced safety systems were estimated using a statistical model that determined crash rates based on the frequency and severity of rear-end conflicts encountered during the FOT.

The Volvo IVI FOT independent evaluation team performed also a benefit-cost analysis (BCA) to determine the net economic benefits of deploying the advanced safety systems.

Sources of information

- Final Report Evaluation of the Volvo Intelligent Vehicle Initiative Field Operational Test Version 1.3 by Batelle (Jan 2007, Contract No. DTFH61-96-C-00077, Task Order 7721)

- Summary paper: